Plasticizer-inclusive polymeric-inorganic hybrid layer for a lithium anode in a lithium-sulfur battery

ABSTRACT

A lithium-sulfur battery including an anode structure, a cathode, a separator, and an electrolyte is provided. A protective layer may form within the anode structure responsive to operational discharge-charge cycling of the lithium-sulfur battery. The protective layer may include a polymeric backbone chain formed of interconnected carbon atoms collectively defining a segmental motion of the protective layer. Additional polymeric chains may be cross-linked to one another and at least some carbon atoms of the polymeric backbone chain. Each additional polymeric chain may be formed of interconnected monomer units. A plasticizer may be dispersed throughout the protective layer without covalently bonding to the polymeric backbone chain. The plasticizer may separate adjacent monomer units of at least some additional polymeric chains. Increasing separation of adjacent monomer units increases a cooperative segmental mobility of the additional polymeric chains and ionic conductivity of the protective layer.

CROSS-REFERENCE TO RELATED APPLICATIONS

This Patent Application is a continuation-in-part application and claimspriority to U.S. patent application Ser. No. 17/666,753 entitled“POLYMERIC-INORGANIC HYBRID LAYER FOR A LITHIUM ANODE” filed on Feb. 8,2022, which is a continuation-in-part application and claims priority toU.S. patent application Ser. No. 17/584,666 entitled “SOLID-STATEELECTROLYTE FOR LITHIUM-SULFUR BATTERIES” filed on Jan. 26, 2022, whichis a continuation-in-part application and claims priority to U.S. patentapplication Ser. No. 17/578,240 entitled “LITHIUM-SULFUR BATTERYELECTROLYTE COMPOSITIONS” filed on Jan. 18, 2022, which is acontinuation-in-part application and claims priority to U.S. patentapplication Ser. No. 17/563,183 entitled “LITHIUM-SULFUR BATTERY CATHODEFORMED FROM MULTIPLE CARBONACEOUS REGIONS” filed on Dec. 28, 2021, whichis a continuation-in-part of and claims priority to U.S. patentapplication Ser. No. 17/383,803 entitled “CARBONACEOUS MATERIALS FORLITHIUM-SULFUR BATTERIES” filed on Jul. 23, 2021. This PatentApplication also claims priority to Provisional Patent Application No.63/149,894 entitled “CATHODE FOR A LITHIUM SULFUR BATTERY” filed on Feb.16, 2021. The disclosures of all prior Applications are assigned to theassignee hereof, and are considered part of and are incorporated byreference in this Patent Application in their respective entireties.

TECHNICAL FIELD

This disclosure relates generally to a lithium-sulfur battery, and, moreparticularly, to a protective layer, disposed on an anode of thelithium-sulfur battery, configured to prevent polysulfide species fromcontacting the anode.

DESCRIPTION OF RELATED ART

Recent developments in batteries allow consumers to use electronicdevices in many new applications. However, further improvements inbattery technology are desirable.

SUMMARY

This Summary is provided to introduce in a simplified form a selectionof concepts that are further described below in the DetailedDescription. This Summary is not intended to identify key features oressential features of the claimed subject matter, nor is it intended tolimit the scope of the claimed subject matter.

One innovative aspect of the subject matter described in this disclosuremay be implemented as a lithium-sulfur battery including a cathode, ananode structure positioned opposite to the cathode, a separatorpositioned between the anode structure and the cathode, and anelectrolyte dispersed throughout the cathode and in contact with theanode structure. In one implementation, the anode structure may beformed as a single layer of solid lithium, which may output lithiumcations (Li⁺) during operational discharge cycling of the lithium-sulfurbattery. A solid-electrolyte interphase layer may be formed on thesingle layer of solid lithium. A protective layer may form on and atleast partially within the solid-electrolyte interphase layer responsiveto operational discharge-charge cycling of the lithium-sulfur battery.

The protective layer may include a polymeric backbone chain formed ofinterconnected carbon atoms collectively defining a cooperativesegmental mobility of the protective layer. Polymeric chains may becross-linked to one another and to at least some carbon atoms of thepolymeric backbone chain. Each polymeric chain is formed ofinterconnected monomer units. In some aspects, a plasticizer, e.g., anyone or more of a polyethylene glycol (PEG or PEO) based oligomer, anitrile, such as succinonitrile, glutaronitrile, adiponitrile, asolvent, including dimethoxyethane (DME), tetrahydrofuran (THF), diethylether, dioxolane (DOL), tetraethylene glycol dimethyl ether (TEGDME),toluene, bis(2,2-trifluoroethyl ether) (TEE), fluoroethylene carbonate(FEC), diethyl carbonate (DEC), dimethyl carbonate (DMC), propylenecarbonate (PC), ethylene carbonate (EC), may be dispersed throughout theprotective layer without covalently bonding to the polymeric backbonechain. In this way, the plasticizer may separate adjacent monomer unitsof at least some polymeric chains. Increasing separation of adjacentmonomer units may be associated with an increased cooperative segmentalmobility of polymeric chains and ionic conductivity of the protectivelayer. In addition, increasing the plasticizer in the protective layermay be associated with an increase in lithium cation (Li⁺) conductivitythrough the protective layer. In some other aspects, various linearpolymeric and/or oligomeric chains may be chemically (e.g., by covalentbonding) attached to carbon atoms of the polymeric backbone chain toincrease cooperative segmental mobility of the protective layer, andthereby also increase lithium cation (Li⁺) conductivity through theprotective layer. For example, oligomeric substances such aspolyoxypropylenediamine (e.g., JEFFAMINE® M-600) may be associated withan increase in the cooperative segmental mobility of the protectivelayer.

In some aspects, the protective layer may melt at a glass transitiontemperature, such that an increase in the glass transition temperaturemay be associated with a reduction in the cooperative segmental mobilityof the plurality of additional polymeric chains. In some other aspects,a decrease in the cooperative segmental mobility of the plurality ofadditional polymeric chains may be associated with a decrease in lithiumion (Li⁺) conductivity through the protective layer. In this way, insome aspects, an increase in an amount of the plasticizer in theprotective layer may be associated with an increase in the lithium ion(Li⁺) conductivity through the protective layer.

Another innovative aspect of the subject matter described in thisdisclosure may be implemented as a lithium-sulfur battery including acathode, an anode positioned opposite to the cathode, a separatorpositioned between the anode and the cathode, and an electrolytedispersed throughout the cathode and in contact with the anode. In oneimplementation, a protective layer may be formed on the anode as athree-dimensional (3D) polymeric lattice including a first polymericchain and a second polymeric chain positioned opposite one another. Eachof the first and second polymeric chains may include carbon atoms atleast temporarily chemically bonded to oxide ions (O²⁻), fluorine anions(F⁻), and/or nitrate anions (NO₃ ⁻). Lithiumbis(trifluoromethanesulfonyl)imide (LiTFSI) may be dispersed throughoutthe 3D polymeric lattice to dissociate into lithium cations (Li⁺) andTFSI− anions. In this way, the first and second polymeric chains mayform the 3D polymeric lattice with a cross-linking density sufficient totrap TFSI− anions by cross-linking with each other. For example,cross-linking may be initiated upon exposure to an energetic environmentincluding ultraviolet (UV) energy and LiTFSI, such that LiTFSI may serveas a polymerization co-initiator compound.

The first and second polymeric chains may form the 3D polymeric latticethrough cross-linking polymerization reactions, one or more of which mayinclude a ultraviolet (UV) curing that may progress at a curing rate. Insome aspects, the polymerization co-initiator compound may increase thecuring rate. In some instances, the lithium-sulfur battery may includeadditives dispersed uniformly throughout the 3D polymeric lattice. Eachof the additives may include lithium nitrate (LiNO₃), inorganicionically-conductive ceramics including lithium lanthanum zirconiumoxide (LLZO), NASICON-type oxide Li_(1+x)Al_(x)Ti_(2-x)(PO₄)₃ (LATP) orlithium tin phosphorus sulfide (LSPS), or nitrogen-oxygen containingadditives. In this way, inorganic ionically-conductive ceramics may beuniformly embedded in the 3D polymeric lattice and/or uniformlydistributed throughout the protective layer. In addition, the protectivelayer may include desiccated solvents.

Another innovative aspect of the subject matter described in thisdisclosure may be implemented as a lithium-sulfur battery including acathode, an anode positioned opposite to the cathode, a protective layerformed on the anode, a separator positioned between the anode and thecathode, and an electrolyte dispersed throughout the cathode and incontact with the anode. The protective layer may trap various types ofanions. In addition, the protective layer may be formed of multipleingredients including relatively pliable oligomeric epoxy and/or polyolbased compounds (e.g., one or more of which may eliminate formation ofpinholes in the protective layer), a relatively rigid polymeric epoxybased compound, and/or photo-initiator molecules. Lithium-containingsalts may be dispersed uniformly throughout the protective layer todissociate into lithium (Li+) cations and at least one type of anion.

In some instances, the protective layer may be formed on the anoderesponsive to ultraviolet (UV) curing of at least some of the multipleingredients. In addition, in some aspects, the protective layer mayinclude non-reactive diluents including 1,2-Dimethoxyethane (DME),tetrahydrofuran (THF), triethylene glycol dimethyl ether (TEGDME), or2-Methyl-2-oxazoline (MOZ). In some other aspects, the protective layermay include reactive diluents including 1,3-Dioxolane (DOL),3,3-Dimethyloxetane (DMO), 2-Ethyl-2-oxazoline (EOZ), or ε-Caprolactone(CL). In this way, a per-unit formulation weight of the protective layermay be based on a concentration level of non-reactive diluents orreactive diluents relative to ingredients of the protective layer. Inaddition, the reactive diluents may reduce mechanical stress of at leastsome of the cross-linking units within the protective layer.

In some aspects, reactive diluents may be removed from the protectivelayer. In some other aspects, the reactive diluents may remain in theprotective layer after cross-linking of at least some ingredients. Inthis way, retention of reactive diluents in the protective layer aftercross-linking of two or more ingredients improves lithium cation (Li+)diffusion through the electrolyte. In one implementation, the relativelyrigid polymeric epoxy based compound is formed from repeating epoxymonomer units. For example, each of the repeating epoxy monomer unitsmay include 3,4-epoxycyclohexylmethyl 3,4-epoxycyclohexanecarboxylate(ECC), which may cross-link with additional ECC monomer units andproduce a network of polar groups. The network of polar groups may trapat least some anions produced upon dissociation of lithium-containingsalts.

Details of one or more implementations of the subject matter describedin this disclosure are set forth in the accompanying drawings and thedescription below. Other features, aspects, and advantages will becomeapparent from the description, the drawings, and the claims. Note thatthe relative dimensions of the following figures may not be drawn toscale.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a diagram depicting an example battery, according to someimplementations.

FIG. 2 shows a diagram depicting another example battery, according tosome implementations.

FIG. 3 shows a diagram of an example electrode of a battery, accordingto some implementations.

FIG. 4 shows a diagram a diagram of a portion of an example battery thatincludes a protective lattice, according to some implementations.

FIG. 5 shows a diagram of an anode structure including a tin fluoride(SnF₂) layer, according to some implementations.

FIG. 6 shows a diagram of an enlarged portion of the anode structure ofFIG. 5, according to some implementations.

FIG. 7 shows a diagram of a polymeric network of a battery, according tosome implementations.

FIG. 8A shows a diagram of an example carbonaceous particle with gradedporosity, according to some implementations.

FIG. 8B shows a diagram of an example of a tri-zone particle, accordingto some implementations.

FIG. 8C shows an example step function representative of the tri-zoneparticle of FIG. 8B, according to some implementations.

FIG. 8D shows a graph depicting an example distribution of pore volumeversus pore width of an example carbonaceous particle, according to someimplementations.

FIGS. 9A and 9B show electron micrographs of example carbonaceousparticles, aggregates, and/or agglomerates depicted in FIG. 8A and/orFIG. 8B, according to some implementations.

FIGS. 10A and 10B show transmission electron microscope (TEM) images ofcarbonaceous particles treated with carbon dioxide (CO₂), according tosome implementation.

FIG. 11 shows a diagram depicting carbon porosity types prevalent in theanodes and/or the cathodes of the present disclosure, according to someimplementations.

FIG. 12 shows a graph depicting cumulative pore volume versus pore widthfor micropores and mesopores dispersed throughout the anode or cathodeof a battery, according to some implementations.

FIG. 13 shows graphs depicting battery performance per cycle number,according to some implementations.

FIG. 14 shows a bar chart depicting capacity per cycle number, accordingto some implementations.

FIG. 15 shows graphs depicting battery performance per cycle number,according to some implementations.

FIG. 16 shows a graph depicting battery discharge capacity per cyclenumber, according to some implementations.

FIG. 17 shows a graph depicting battery discharge capacity per cyclenumber, according to some implementations.

FIG. 18 shows a graph depicting battery specific discharge capacity forvarious TBT-containing electrolyte mixtures, according to someimplementations.

FIG. 19 shows graphs depicting battery specific discharge capacity percycle number for the battery of FIG. 1, according to someimplementations.

FIG. 20 shows graphs depicting battery specific discharge capacity anddischarge capacity retention per cycle number for the battery of FIG. 2,according to other implementations.

FIG. 21 shows graphs depicting battery specific discharge capacity anddischarge capacity retention per cycle number for the battery of FIG. 2,according to some other implementations.

FIG. 22 shows a diagram of an example cathode of a battery, according tosome implementations.

FIGS. 23-25 show graphs depicting specific discharge capacity per cyclenumber, according to some implementations.

FIG. 26A shows a diagram depicting an example battery, according to someimplementations.

FIG. 26B shows a diagram depicting an example battery, according to someimplementations.

FIG. 27 shows a graph depicting voltage drop per specific capacity,according to some implementations.

FIG. 28 shows a diagram depicting an example battery, according to someimplementations.

FIG. 29 shows a diagram depicting an example cathode of the battery ofFIG. 28, according to some implementations.

FIG. 30 shows a diagram depicting the protective layer of the battery ofFIG. 28, according to some implementations.

FIG. 31A shows a micrograph of an example baseline protective layer,according to some implementations.

FIG. 31B shows a micrograph of the protective layer of the battery ofFIG. 28, according to some implementations.

FIG. 32 shows a micrograph of a cutaway of the protective layer of thebattery of FIG. 28, according to some implementations.

FIG. 33A shows an example cross-linking density of the protective layerof the battery of FIG. 28, according to some implementations.

FIG. 33B shows another example cross-linking density of the protectivelayer of the battery of FIG. 28, according to some implementations.

FIG. 34 shows an example ring-opening (ROP) mechanism fortriarylsulfonium salt (Ar₃S⁺MtXn⁻), according to some implementations.

FIG. 35 shows several example onium salts suitable for usage as cationicphoto-initiators for the protective layer of the battery of FIG. 28,according to some implementations.

FIG. 36 shows a several example monomers of various cationicphoto-polymerizable compositions suitable for forming the protectivelayer of the battery of FIG. 28, according to some implementations.

FIG. 37 shows ultraviolet (UV) curable monomers suitable for forming theprotective layer of the battery of FIG. 28, according to someimplementations.

FIG. 38 shows several example non-reactive diluents suitable for usageas additives to adjust dilution levels in UV-curable formulationsprepared with the UV curable monomers of FIG. 37, according to someimplementations.

FIG. 39 shows several example reactive diluents suitable for usage asadditives to adjust dilution levels in UV-curable formulations preparedwith the UV curable monomers of FIG. 37, according to someimplementations.

FIG. 40A shows a graph of capacity (% of initial) against cycle number,according to some implementations.

FIG. 40B shows a graph of capacity (mAh/g) against cycle number,according to some implementations.

FIG. 41A shows another graph of capacity (% of initial) against cyclenumber, according to some implementations.

FIG. 41B shows another graph of capacity (mAh/g) against cycle number,according to some implementations.

FIG. 42A shows a diagram depicting an example battery, according to someimplementations.

FIG. 42B shows an enlarged section of the battery of FIG. 42A, accordingto some implementations.

Like reference numbers and designations in the various drawings indicatelike elements.

DETAILED DESCRIPTION

The following description is directed to some example implementationsfor the purposes of describing innovative aspects of this disclosure.However, a person having ordinary skill in the art will readilyrecognize that the teachings herein can be applied in a multitude ofdifferent ways. The described implementations can be implemented in anytype of electrochemical cell, battery, or battery pack, and can be usedto compensate for various performance related deficiencies. As such, thedisclosed implementations are not to be limited by the examples providedherein, but rather encompass all implementations contemplated by theattached claims. Additionally, well-known elements of the disclosurewill not be described in detail or will be omitted so as not to obscurethe relevant details of the disclosure.

Batteries typically include several electrochemical cells that can beconnected to each other to provide electric power to a wide variety ofdevices such as (but not limited to) mobile phones, laptops, electricvehicles (EVs), factories, and buildings. Certain types of batteries,such as lithium-ion or lithium-sulfur batteries, may be limited inperformance by the type of electrolyte used or by uncontrolled batteryside reactions. As a result, optimization of the electrolyte may improvethe cyclability, the specific discharge capacity, the discharge capacityretention, the safety, and the lifespan of a respective battery. Forexample, in an unused or “fresh” battery, lithium cations (Li⁺) aretransported freely from the anode to the cathode upon activation andlater during initial and subsequent discharge cycles. Then, duringbattery charge cycles, lithium cations (Li⁺) may be forced to migrateback from their electrochemically favored positions in the cathode tothe anode, where they are stored for subsequent use. This cyclicaldischarge-charge process associated with rechargeable batteries canresult in the generation of undesirable chemical species that caninterfere with the transport of lithium cations (Li⁺) to and from thecathode during respective discharge and charge of the battery.Specifically, lithium-containing polysulfide intermediate species(referred to herein as “polysulfides”) are generated when lithiumcations (Li⁺) interact with elemental sulfur (or, in someconfigurations, lithium sulfide, Li₂S) present in the cathode. Thesepolysulfides are soluble in the electrolyte and, as a result, diffusethroughout the battery during operational cycling, thereby resulting inloss of active material from cathode. Generation of excessiveconcentration levels of polysulfides can result in unwanted batterycapacity decay and cell failure during operational cycling, potentiallyreducing the driving range for electric vehicles (EVs) and increasingthe frequency with which such EVs need recharging.

In some cases, polysulfides participate in the formation of inorganiclayers in a solid electrolyte interphase (SEI) provided in the battery.In one example, the anode may be protected by a stable inorganic layerformed in the electrolyte and containing 0.020 M Li₂S₅ (0.10 M sulfur)and 5.0 wt. % LiNO₃. The anode with a lithium fluoride and polysulfides(LiF—Li₂S_(x)) may enrich the SEI and result in a stable Coulombicefficiency of 95% after 233 cycles for Li—Cu half cells, whilepreventing formation of lithium dendrites or other uncontrolled lithiumgrowths that can extend from the anode to the cathode and result in afailed or ruptured cell. However, when polysulfides are generated atcertain concentrations (such as greater than 0.50 M sulfur), formationof the SEI may be hindered. As a result, lithium metal from the anodemay be undesirably etched, creating a rough and imperfect surfaceexposed to the electrolyte. This unwanted deterioration (etching) of theanode due to a relatively high concentration of polysulfides mayindicate that polysulfide dissolution and diffusion may be limitingbattery performance.

In some implementations, the porosity of a carbonaceous cathode may beadjusted to achieve a desired balance between maximizing energy densityand inhibiting the migration of polysulfides into and/or throughout thebattery's electrolyte. As used herein, carbonaceous may refer tomaterials containing or formed of one or more types or configuration ofcarbon. For example, cathode porosity may be higher in sulfur and carboncomposite cathodes than in conventional lithium-ion battery electrodes.Denser electrodes with relatively low porosity may minimize electrolyteintake, parasitic weight, and cost. Sulfur utilization may be limited bythe solubility of polysulfides and conversion from those polysulfidesinto lithium sulfide (Li₂S). The conversion of polysulfides into lithiumsulfide may be based on the accessible surface area of the cathode.Aspects of the present disclosure recognize that cathode porosity may beadjusted based on electrolyte compositions to maximize batteryvolumetric energy density. In addition, or in the alternative, one ormore protective layers or regions can be added to surfaces of thecathode and/or the anode exposed to the electrolyte to adjust cathodeporosity levels. In some aspects, these protective layers or regions caninhibit the undesirable migration of polysulfides throughout thebattery.

Various aspects of the subject matter disclosed herein relate to alithium-sulfur battery including a liquid-phase electrolyte, which mayinclude a ternary solvent package and one or more additives. In someimplementations, the lithium-sulfur battery may include a cathode, ananode positioned opposite to the cathode, and an electrolyte. Thecathode may include several regions, where each region may be defined bytwo or more carbonaceous structures adjacent to and in contact with eachother. In some instances, the electrolyte may be interspersed throughoutthe cathode and in contact with the anode. In some aspects, theelectrolyte may include a ternary solvent package and4,4′-thiobisbenzenethiol (TBT). In other instances, the electrolyte mayinclude the ternary solvent package and 2-mercaptobenzothiazole (MBT).

In various implementations, the ternary solvent package may include1,2-Dimethoxyethane (DME), 1,3-Dioxolane (DOL), tetraethylene glycoldimethyl ether (TEGDME) and one or more additives, which may include alithium nitrate (LiNO₃), all which may be in a liquid-phase. In someimplementations, the ternary solvent package may be prepared by mixingapproximately 5,800 microliters (μL) of DME, 2,900 microliters (μL) ofDOL, and 1,300 microliters (μL) of TEGDME with one another to create amixture. Approximately 0.01 mol of lithiumbis(trifluoromethanesulfonyl)imide (LiTFSI) may be dissolved into theternary solvent package to produce an approximate dilution level of 1 MLiTFSI in DME:DOL:TEGDME at a volume ratio of 2:1:1 includingapproximately 2 weight percent (wt. %) lithium nitrate. In otherimplementations, the ternary solvent package may be prepared with 2,000microliters (μL) of DME, 8,000 microliters (μL) of DOL, and 2,000microliters (μL) of TEGDME and include approximately 0.01 mol ofdissolved lithium bis(trifluoromethanesulfonyl)imide (LiTFSI). In someaspects, the ternary solvent package may be prepared at a firstapproximate dilution level of 1 molar (M) LiTFSI in a mixture ofDME:DOL:TEGDME. In other instances, the ternary solvent package may beprepared at a second approximate dilution level of approximately 1 MLiTFSI in DME:DOL:TEGDME at an approximate volume ratio of 1:4:1 andinclude either an addition of 5M TBT solution or an addition of 5M MBTsolution, or an addition of other additives and/or chemical substances.

In various implementations, each carbonaceous structure may include arelatively high-density outer shell region and a relatively low-densitycore region. In some aspects, the core region may be formed within aninterior portion of the outer shell region. The outer shell region mayhave a carbon density between approximately 1.0 grams per cubiccentimeter (g/cc) and 3.5 g/cc. The core region may have a carbondensity of between approximately 0.0 g/cc and 1.0 g/cc or some otherrange lower than the first carbon density. In other implementations,each carbonaceous structure may include an outer shell region and coreregion having the same or similar densities, for example, such that thecarbonaceous structure does not include a graded porosity.

Various regions of the cathode may include microporous channels,mesoporous channels, and macroporous channels interconnected to eachother to form a porous network extending from the outer shell region tothe core region. For example, in some aspects, the porous network mayinclude pores that each have a principal dimension of approximately 1.5nm.

In some implementations, one or more portions of the porous network maytemporarily micro-confine electroactive materials such as (but notlimited to) elemental sulfur within the cathode, which may increasebattery specific capacity by complexing with lithium cations (Li⁺). Insome aspects, the ternary solvent package may have a tunable polarity, atunable solubility, and be capable of transporting lithium cations(Li⁺). In addition, the ternary solvent package may at least temporarilysuspend polysulfides (PS) during charge-discharge cycles of the battery.

Particular implementations of the subject matter described in thisdisclosure can be implemented to realize one or more potentialadvantages. In some implementations, the porous network formed by theinterconnection of microporous, mesoporous, and macroporous channelswithin the cathode may include a plurality of pores having a multitudeof different pore sizes. In some implementations, the plurality of poresmay include micropores having a pore size less than approximately 2 nm,may include mesopores having a pore size between approximately 5 and 50nm, and may include macropores having a pore size greater thanapproximately 50 nm. The micropores, mesopores, and macropores maycollectively mitigate the undesirable migration or diffusion ofpolysulfides throughout the electrolyte. Since the poly sulfide shuttleeffect may result in the loss of active material from the cathode, theability to mitigate or reduce the polysulfide shuttle effect canincrease battery performance.

In one implementation, the micropores may have a pore size ofapproximately 1.5 nm selected to micro-confine elemental sulfur (S₈, orsmaller chains/fragments of sulfur, for example in the form of S₂, S₄ orS₆) pre-loaded into the cathode. The micro-confinement of elementalsulfur within the cathode may allow TBT or MBT complexes generatedduring battery cycling to inhibit the migration of long-chainpolysulfides within the mesopores of the cathode. Accumulation of theselong-chain polysulfides within the mesopores of the cathode may causethe cathode to volumetrically expand to retain the polysulfides andthereby reduce the polysulfide shuttle effect. Accordingly, lithiumcations (Li⁺) may continue to transport freely between the anode and thecathode via the electrolyte without being blocked or impeded by thepolysulfides. The free movement of lithium cations (Li⁺) throughout theelectrolyte without interference by polysulfides can increase batteryperformance.

In addition, or the alternative, one or more protective layers, sheaths,films, and/or regions (collectively referred to herein as “protectivelayers”) may be disposed on the anode and/or the cathode and/or theseparator and in contact with the electrolyte. The protective layers mayinclude materials capable of binding with polysulfides to impedepolysulfide migration and prevent lithium dendrite formation. In someaspects, the protective layers may be arranged in differentconfigurations and used with any of the electrolyte chemistries and/orcompositions disclosed herein, which in turn may result in completetunability of the battery.

In one implementation, carbonaceous materials may be grafted withfluorinated polymer chains and deposited on one or more exposed surfacesof the anode. The fluorinated polymer chains can be cross-linked into apolymeric network on contact with Lithium metal from the anode surfacevia the Wurtz reaction. The cross-linked polymeric network formationmay, in turn, suppress Lithium metal dendrite formation associated withthe anode, and may also generate Lithium fluoride. Fluorinated polymerswithin the polymeric network may participate in chemical reactionsduring battery operational cycling to yield Lithium fluoride. Formationof the lithium fluoride may involve the chemical binding of lithiumcations (Li⁺) from the electrolyte with fluorine ions.

In addition, or the alternative, the polymeric network may be combinedwith any of the electrolyte chemistries and/or compositions disclosedherein and/or a protective sheath disposed on the cathode. In oneimplementation, the protective sheath can be formed by combiningcompounds containing di-functional, or higher functionality Epoxy andAmine or Amide compounds. Their intermolecular cross-linking wouldresult in formation of 3D network with high chemical resistance todissolution in electrolyte. Composition, for example, may include atri-functional epoxy compound and a di-amine oligomer-based compound,which may react with each other to produce a protective lattice that canbind to polysulfides generated in the cathode and prevent theirmigration or diffusion into the electrolyte. In addition, the protectivelattice may diffuse through one or more cracks that may form in thecathode due to battery cycling. The protective lattice, when diffusedthroughout such cracks formed in the cathode, may increase thestructural integrity of the cathode, and reduce potential rupture of thecathode associated with volumetric expansion.

In various implementations, one or more of the disclosed batterycomponents may be combined with a conformal coating disposed on edges orsurfaces of the anode exposed to the electrolyte. In someimplementations, the conformal coating may include a graded interfacelayer that may replace the polymeric network. In some aspects, thegraded interface layer may include a tin fluoride layer and atin-lithium alloy region formed between the tin fluoride layer and theanode. The tin-lithium alloy region may form a layer of lithium fluorideuniformly dispersed between the anode and the tin-fluoride layer inresponse to operational cycling of the battery.

In various implementations, a lithium-sulfur battery employing variousaspects of the present disclosure may include an electroactive materialextracted from an external source, e.g., a subterranean source and/or anextraterrestrial subterranean source. In such implementations, thecathode may be prepared as a sulfur-free cathode including functionalpores that may micro-confine the electroactive material within thecathode. In some aspects, the cathode may include aggregates including amultitude of carbonaceous particles joined together, and may includeagglomerates including a multitude of the aggregates joined together. Inone implementation, the carbonaceous materials used to form the cathode(and/or the anode) may be tuned to define unique pore sizes, sizeranges, and volumes. In some implementations, the carbonaceous particlesmay include non-tri-zone particles with and without tri-zone particles.In other implementations, the carbonaceous particles may not includetri-zone particles. Each tri-zone particle may include micropores,mesopores, and macropores, and both the non-tri-zone and tri-zoneparticles may each have a principal dimension in an approximate range of20 nm to 300 nm. Each of the carbonaceous particles may includecarbonaceous fragments nested within each other and separated fromimmediate adjacent carbonaceous fragments by mesopores. In some aspects,each of the carbonaceous particles may have a deformable perimeter thatchanges in shape and coalesces with adjacent materials.

Some of the pores may be distributed throughout the plurality ofcarbonaceous fragments and/or the deformable perimeters of thecarbonaceous particles. In various implementations, mesopores may beinterspersed throughout the aggregates, and macropores may beinterspersed throughout the plurality of agglomerates. In oneimplementation, each mesopore may have a principal dimension between 3.3nanometers (nm) and 19.3 nm, each aggregate may have a principaldimension in an approximate range between 10 nm and 10 micrometers (μm),and each agglomerate may have a principal dimension in an approximaterange between 0.1 μm and 1,000 μm. As further described below, specificcombinations of pore sizes matched with unique electrolyte formulationsand protective layers can be used to reduce or mitigate the harmfuleffects of unwanted polysulfide diffusion, which may further increasebattery performance.

FIG. 1 shows an example battery 100, according to some implementations.The battery 100 may be a lithium-sulfur electrochemical cell, alithium-ion battery, or a lithium-sulfur battery. The battery 100 mayhave a body 105 that includes a first substrate 101, a second substrate102, a cathode 110, an anode 120 positioned opposite to the cathode 110,and an electrolyte 130. In some aspects, the first substrate 101 mayfunction as a current collector for the anode 120, and the secondsubstrate 102 may function as a current collector for the cathode 110.The cathode 110 may include a first thin film 111 deposited onto thesecond substrate 102, and may include a second thin film 112 depositedonto the first thin film 111. In some implementations, the electrolyte130 may be a liquid-phase electrolyte including one or more additivessuch as lithium nitrate, tin fluoride, lithium iodide, lithiumbis(oxalate)borate (LiBOB), cesium nitrate, cesium fluoride, ionicliquids, lithium fluoride, fluorinated ether, TBT, MBT, DPT and/or thelike. Suitable solvent packages for these example additives may includevarious dilution ratios, including 1:1:1 of 1,3-dioxolane (DOL),1,2-dimethoxyethane, (DME), tetraethylene glycol dimethyl ether(TEGDME), and/or the like.

Although not shown for simplicity, in one implementation, a lithiumlayer may be electrodeposited on one or more exposed carbon surfaces ofthe anode 120. In some instances, the lithium layer may includeelemental lithium provided by the ex-situ electrodeposition of lithiumonto exposed surfaces of the anode 120. In some aspects, the lithiumlayer may include lithium, calcium, potassium, magnesium, sodium, and/orcesium, where each metal may be ex-situ deposited onto exposed carbonsurfaces of the anode 120. The lithium layer may provide lithium cations(Li⁺) available for transport to-and-from the cathode 110 duringoperational cycling of the battery 100. As a result, the battery 100 maynot need an additional lithium source for operation. Instead of usinglithium sulfide, elemental sulfur (S₈) may be pre-loaded in variouspores or porous networks formed in the cathode 110. During operationalcycling of the battery, the elemental sulfur may form lithium-sulfurcomplexes that can micro-confine (at least temporarily) greater amountsof lithium than conventional cathode designs. As a result, the battery100 may outperform batteries that rely on such conventional cathodedesigns.

In various implementations, the lithium layer may dissociate and/orseparate into lithium cations (Li⁺) 125 and electrons 174 during adischarge cycle of the battery 100. The lithium cations (Li⁺) 125 maymigrate from the anode 120 towards the cathode 110 through theelectrolyte 130 to their electrochemically favored positions within thecathode 110, as depicted in the example of FIG. 1. As the lithiumcations (Li⁺) 125 move through the electrolyte 130, electrons 174 arereleased from lithium cations (Li⁺) 125 and become available to carrycharge, and therefore conduct an electric current, between the anode 120and cathode 110. As a result, the electrons 174 may travel from theanode 120 to the cathode 110 through an external circuit to power anexternal load 172. The external load 172 may be any suitable circuit,device, or system such as (but not limited to) a lightbulb, consumerelectronics, or an electric vehicle (EV).

In some implementations, the battery 100 may include a solid-electrolyteinterphase layer 140. The solid-electrolyte interphase layer 140 may, insome instances, be formed artificially on the anode 120 duringoperational cycling of the battery 100. In such instances, thesolid-electrolyte interphase layer 140 may also be referred to as anartificial solid-electrolyte interphase, or A-SEI. The solid-electrolyteinterphase layer 140, when formed as an A-SEI, may include tin,manganese, molybdenum, and/or fluorine compounds. Specifically, themolybdenum may provide cations, and the fluorine compounds may provideanions. The cations and anions may interact with each other to producesalts such as tin fluoride, manganese fluoride, silicon nitride, lithiumnitride, lithium nitrate, lithium phosphate, manganese oxide, lithiumlanthanum zirconium oxide (LLZO, Li₇La₃Zr₂O₁₂), etc. In some instances,the A-SEI may be formed in response to exposure of lithium cations (Li⁺)125 to the electrolyte 130, which may include solvent-based solutionsincluding tin and/or fluorine.

In various implementations, the solid-electrolyte interphase layer 140may be artificially provided on the anode 120 prior to activation of thebattery 100. Alternatively, in one implementation, the solid-electrolyteinterphase layer 140 may form naturally, e.g., during operationalcycling of the battery 100, on the anode 120. In some instances, thesolid-electrolyte interphase layer 140 may include an outer layer ofshielding material that can be applied to the anode 120 as amicro-coating. In this way, formation of the solid-electrolyteinterphase layer 140 on portions of the anode 120 facing the electrolyte130 may result from electrochemical reduction of the electrolyte 130,which in turn may reduce uncontrolled decomposition of the anode 120.

In some implementations, the battery 100 may include a barrier layer 142that flanks the solid-electrolyte interphase layer 140, for example, asshown in FIG. 1. The barrier layer 142 may include a mechanical strengthenhancer 144 coated and/or deposited on the anode 120. In some aspects,the mechanical strength enhancer 144 may provide structural support forthe battery 100, may prevent lithium dendrite formation from the anode120, and/or may prevent protrusion of lithium dendrite throughout thebattery 100. In some implementations, the mechanical strength enhancer144 may be formed as a protective coating over the anode 120, and mayinclude one or more carbon allotropes, carbon nano-onions (CNOs),nanotubes (CNTs), reduced graphene oxide, graphene oxide (GO), and/orcarbon nano-diamonds. In some instances, the solid-electrolyteinterphase layer 140 may be formed within the mechanical strengthenhancer 144.

In some implementations, the first substrate 101 and/or the secondsubstrate 102 may be a solid copper metal foil and may influence theenergy capacity, rate capability, lifespan, and long-term stability ofthe battery 100. For example, to control energy capacity and otherperformance attributes of the battery 100, the first substrate 101and/or the second substrate 102 may be subject to etching, carboncoating, or other suitable treatment to increase electrochemicalstability and/or electrical conductivity of the battery 100. In otherimplementations, the first substrate 101 and/or the second substrate 102may include or may be formed from a selection of aluminum, copper,nickel, titanium, stainless steel and/or carbonaceous materialsdepending on end-use applications and/or performance requirements of thebattery 100. For example, the first substrate 101 and/or the secondsubstrate 102 may be individually tuned or tailored such that thebattery 100 meets one or more performance requirements or metrics.

In some aspects, the first substrate 101 and/or the second substrate 102may be at least partially foam-based or foam-derived, and can beselected from any one or more of metal foam, metal web, metal screen,perforated metal, or sheet-based three-dimensional (3D) structures. Inother aspects, the first substrate 101 and/or the second substrate 102may be a metal fiber mat, metal nanowire mat, conductive polymernanofiber mat, conductive polymer foam, conductive polymer-coated fiberfoam, carbon foam, graphite foam, or carbon aerogel. In some otheraspects, the first substrate 101 and/or second substrate 102 may becarbon xerogel, graphene foam, graphene oxide foam, reduced grapheneoxide foam, carbon fiber foam, graphite fiber foam, exfoliated graphitefoam, or any combination thereof.

FIG. 2 shows another example battery 200, according to someimplementations. The battery 200 may be similar to the battery 100 ofFIG. 1 in many respects, such that description of like elements is notrepeated herein. In some implementations, the battery 200 may be anext-generation battery, such as a lithium-metal battery and/or asolid-state battery featuring a solid-state electrolyte. In otherimplementations, the battery 200 may include an electrolyte 230 and maytherefore include any of the protective layers and/or electrolytechemistries or compositions disclosed herein.

In some other implementations, the electrolyte 230 may be solid orsubstantially solid. For example, in some instances, the electrolyte 230may begin in a gel phase and then later solidify upon activation of thebattery 200. The battery 200 may reduce specific capacity or energylosses associated with the polysulfide shuttle effect by replacingconventional carbon scaffolded anodes with a single solid metal layer oflithium deposited in an initially empty cavity. For example, while theanode 120 of the battery 100 of FIG. 1 may include carbon scaffolds, theanode 220 of the battery 200 of FIG. 2 may be a lithium-metal anodedevoid of any carbon material. In one implementation, the lithium-metalanode may be formed as a single solid lithium metal layer and referredto as a “lithium metal anode.”

Energy density gains associated with various cathode materials may bebased on whether lithium metal is pre-loaded into the cathode 210 and/oris prevalent in the electrolyte 230. Either the cathode 210 and/or theelectrolyte 230 may provide lithium available for lithiation of theanode 220. For example, batteries having high-capacity cathodes may needthicker or energetically denser anodes in order to supply the increasedquantities of lithium needed for usage by the high-capacity cathodes. Insome implementations, the anode 220 may include scaffolded carbonaceousstructures capable of being incrementally filled with lithium depositedtherein. These carbonaceous structures may be capable of retaininggreater amounts of lithium within the anode 220 as compared toconventional graphitic anodes, which may be limited to solely hostinglithium intercalated between alternating graphene layers or may beelectroplated with lithium. For example, conventional graphitic anodesmay use six carbon atoms to hold a single lithium atom. In contrast, byusing a pure lithium metal anode, such as the anode 220, batteriesdisclosed herein may reduce or even eliminate carbon use in the anode220, which may allow the anode 220 to store greater amounts of lithiumin a relatively smaller volume than conventional graphitic anodes. Inthis way, the energy density of the battery 200 may be greater thanconventional batteries of a similar size.

Lithium metal anodes, such as the anode 220, may be prepared to functionwith a solid-state electrolyte designed to inhibit the formation andgrowth of lithium dendrites from the anode. In some aspects, a separator250 may further limit dendrite formation and growth. The separator 250may have a similar ionic conductivity as the electrolyte 130 of FIG. 1yet still reduce lithium dendrite formation. In some aspects, theseparator 250 may be formed from a ceramic containing material and may,as a result, fail to chemically react with metallic lithium. As aresult, the separator 250 may be used to control lithium ion transportthrough pores dispersed across the separator 250 while concurrentlypreventing a short-circuit by impeding the flow or passage of electronsthrough the electrolyte 230.

In one implementation, a void space (not shown for simplicity) may beformed within the battery 200 at or near the anode 220. Operationalcycling of the battery 200 in this implementation may result in thedeposition of lithium into the void space. As a result, the void spacemay become or transform into a lithium-containing region (such as asolid lithium metal layer) and function as the anode 220. In someaspects, the void space may be created in response to chemical reactionsbetween a metal-containing electrically inactive component and agraphene-containing component of the battery 200. Specifically, thegraphene-containing component may chemically react with lithiumdeposited into the void space during operational cycling and producelithiated graphite (LiC₆) or a patterned lithium metal. The lithiatedgraphite produced by the chemical reactions may generate or lead to thegeneration and/or liberation of lithium cations (Li⁺) and/or electronsthat can be used to carry electric charge or a “current” between theanode 220 and the cathode 210 during discharge cycles of the battery200.

And, in implementations for which the anode 220 is a solid lithium metallayer, the battery 200 may be able to hold more electroactive materialand/or lithium per unit volume (as compared to batteries with scaffoldedcarbon and/or intercalated lithiated graphite anodes). In some aspects,the anode 220, when prepared as a solid lithium metal layer, may resultin the battery 200 having a higher energy density and/or specificcapacity than batteries with scaffolded carbon and/or intercalatedlithiated graphite anodes, thereby resulting in longer discharge cycletimes and additional power output per unit time. In instances for whichuse of a solid-state electrolyte is not desired or not optimal, theelectrolyte 230 of the battery 200 of FIG. 2 may be prepared with any ofthe liquid-phase electrolyte chemistries and/or compositions disclosedherein. In addition, or in the alternative, the electrolyte 230 mayinclude lithium and/or lithium cations (Li⁺) available for cyclicaltransport from the anode 220 to the cathode 210 and vice-versa duringdischarge and charge cycles, respectively.

To reduce the migration of polysulfides 282 generated from elementalsulfur 281 pre-loaded in the cathode 210 into the electrolyte 230, thebattery 200 may include one or more unique polysulfide retentionfeatures. For example, given that polysulfides are soluble in theelectrolyte 230, some polysulfides may be expected to drift or migratefrom the cathode 210 towards the anode 220 due to differences inelectrochemical potential, chemical gradients, and/or other phenomena.The migration of polysulfides 282, especially long-chain formpolysulfides, may impede the transport of lithium cations (Li⁺) from theanode 220 to the cathode 210, which in turn may reduce the number ofelectrons available to generate an electric current that can power aload 272, such as an electric vehicle (EV). In some aspects, lithiumcations (Li⁺) 225 may be transported from one or more start positions226 in or near the anode 220 along transport pathways to one or more endpositions 227 in or near the cathode 210, as depicted in the example ofFIG. 2.

In some implementations, a polymeric network 285 may be disposed on theanode 220 to reduce the uncontrolled migration of polysulfides 282 fromthe anode 220 to the cathode 210. The polymeric network 285 may includeone or more layers of carbonaceous materials grafted with fluorinatedpolymer chains cross-linked with each other via the Wurtz reaction uponexposure to Lithium anode surface. The carbonaceous materials in thepolymeric network 285, which may include (but are not limited tographene, few layer graphene, FLG, many layer graphene, and MLG), may bechemically grafted with fluorinated polymer chains containingcarbon-fluorine (C—F) bonds. These C—F bonds may chemically react withlithium metal from the surface of the anode 220 to produce highly ionicCarbon-Lithium bonds (C—Li). These formed C—Li bonds, in turn, may reactwith C—F bonds of polymer chains to form new Carbon-Carbon bonds thatcan also cross-link the polymer chains into (and thereby form) thepolymeric network and generate lithium fluoride (LiF).

The resulting lithium fluoride may be uniformly distributed along theentire perimeter of the polymeric network 285, such that lithium cations(Li⁺) are uniformly consumed to produce an interface layer 283 that mayform or otherwise include lithium fluoride during battery cycling. Theinterface layer 283 may extend along a surface or portion of the anode220 facing the cathode 210, as shown in FIG. 2. As a result, the lithiumcations (Li⁺) 225 are less likely to combine and/or react with eachother and are more likely to combine and/or react with fluorine atomsmade available by the fluorinated polymer chains in the polymericnetwork 285. The resulting reduction of lithium-lithium chemicalreactions decreases lithium-lithium bonding responsible for undesirablelithium-metal dendrite formation. In addition, in some implementations,the polymeric network 285 may replace the interphase layer 240 thateither naturally or artificially develops between the anode 220 and theelectrolyte 230.

In one implementation, the interface layer 283 of the polymeric network285 is in contact with the anode 220, and a protective layer 284 isdisposed on top of the interface layer 283 (such as between theinterface layer 283 and the interphase layer 240). In some aspects, theinterface layer 283 and the protective layer 284 may collectively definea gradient of cross-linked fluoropolymer chains of varying degrees ofdensity, for example, as described with reference to FIG. 7.

In some other implementations, the battery 200 may include a protectivelattice 280 disposed on the cathode 210. The protective lattice 280 mayinclude a tri-functional epoxy compound and a di-amine oligomer-basedcompound that may chemically react with each other to produce nitrogenand oxygen atoms. The nitrogen and oxygen atoms made available by theprotective lattice 280 can bind with the polysulfides 282, therebyconfining the polysulfides 282 within the cathode 210 and/or theprotective lattice 280. Either of the cathode 210 and/or the protectivelattice 280 may include carbon-carbon bonds and/or regions capable offlexing and/or volumetrically expanding during operational cycling ofthe battery 200, which may confine polysulfides 282 generated during theoperational cycling to the cathode 210.

The electrolyte 130 of FIG. 1 and the electrolyte 230 of FIG. 2 may beprepared according to one or more recipes disclosed herein. For example,a ternary solvent package used in the electrolyte 130 and/or theelectrolyte 230 may include DME, DOL and TEGDME. In one implementation,a solvent mixture may be prepared by mixing 5800 μL DME, 2900 μL DOL and1300 μL TEGDME and stirring at room temperature (77° F. or 25° C.).Next, 0.01 mol (2,850.75 mg) of LiTFSI may be weighed. Afterwards, the0.01 mol of LiTFSI may be dissolved in solvent mixture by stirring atroom temperature to prepare approximately 10 mL 1 M LiTFSI inDME:DOL:TEGDME (volume:volume:volume 1:4:1). Finally, approximately 223mg LiNO₃ may be added to 10 mL solution to produce 10 mL 1 M LiTFSI inDME:DOL:TEGDME (volume:volume:volume=58:29:13) with approximately 2 wt.% LiNO₃.

In addition, or the alternative, a ternary solvent package used in theelectrolyte 130 and/or the electrolyte 230 may include DME, DOL, TEGDME,and TBT or MBT. A solvent mixture may be prepared by mixing 2,000 μLDME, 8,000 μL DOL and 2,000 μL TEGDME and stirring at room temperature(68° F. or 25° C.). Next, 0.01 mol (2,850.75 mg) of LiTFSI may beweighed and dissolved in approximately 3 mL of the solvent mixture bystirring at room temperature. Next, the dissolved LiTFSI and anadditional solvent mixture (˜8,056 mg) may be mixed in a 10 mLvolumetric flask to produce approximately 1 M LiTFSI in DME:DOL:TEGDME(volume:volume:volume 1:4:1). Finally, approximately 0.05 mmol (˜12.5mg) TBT or MBT may be added to the 10 mL solution to produce 10 mL of 5MTBT or MBT solution.

FIG. 3 shows an example electrode 300, according to someimplementations. In various implementations, the electrode 300 may beone example of the cathode 110 and/or the anode 120 of the battery 100of FIG. 1. In some other implementations, the electrode 300 may be oneexample of the cathode 210 of the battery 200 of FIG. 2. When theelectrode 300 is implemented as a cathode (such as the cathode 110 ofthe battery 100 of FIG. 1), the electrode 300 may temporarilymicro-confine an electroactive material, such as elemental sulfur, whichmay decrease the amount of sulfur available for reacting with lithium toproduce polysulfides. In some aspects, the electrode 300 may provide anexcess supply of lithium and/or lithium cations (Li⁺) that cancompensate for first-cycle operational losses associated withlithium-based batteries.

In some implementations, the electrode 300 may be porous and receptiveof a liquid-phase electrolyte, such as the electrolyte 130 of FIG. 1.Electroactive species, such as lithium cations (Li⁺) 125 suspended inthe electrolyte 130, may chemically react with elemental sulfurpre-loaded into pores of the electrode 300 to produce polysulfides,which in turn may be trapped in the electrode 300 during batterycycling. In some aspects, the electrode 300 may expand in volume alongone or more flexure points to retain additional quantities ofpolysulfides created during battery cycling. By confining thepolysulfides within the electrode 300, aspects of the subject matterdisclosed herein may allow the lithium cations (Li⁺) 125 to flow freelythrough the electrolyte 130 from the anode 120 to the cathode 110 duringdischarge cycles of the battery 100 (e.g., without being impeded by thepolysulfides). For example, when lithium cations (Li⁺) 125 reach thecathode 110 and react with elemental sulfur contained in or associatedwith the cathode 110, sulfur is reduced to lithium polysulfides(Li₂S_(x)) at decreasing chain lengths according to the orderLi₂S₈→Li₂S₆→Li₂S₄→Li₂S₂ιSi₂S, where 2≤x≤8). Higher order polysulfidesmay be soluble in various types of solvents and/or electrolytes, therebyinterfering with the lithium ion transport necessary for healthy batteryoperation. Retention of such higher order polysulfides by the electrode300 thereby allows the lithium cations (Li⁺) 125 to flow more freelythrough the electrolyte 130, which in turn may increase the number ofelectrons available to carry charge from the anode 120 to the cathode110.

The electrode 300 may include a body 301 defined by a width 305, and mayinclude a first thin film 310 and a second thin film 320. The first thinfilm 310 may include a plurality of first aggregates 312 that jointogether to form a first porous structure 316 of the electrode 300. Insome instances, the first porous structure 316 may have an electricalconductivity between approximately 0 and 500 S/m. In other instances,the first electrical conductivity may be between approximately 500 and1,000 S/m. In some other instances, the first electrical conductivitymay be greater than 1,000 S/m. In some aspects, the first aggregates 312may include carbon nano-tubes (CNTs), carbon nano-onions (CNOs), flakygraphene, crinkled graphene, graphene grown on carbonaceous materials,and/or graphene grown on graphene.

In some implementations, the first aggregates 312 may be decorated witha plurality of first nanoparticles 314. In some instances, the firstnanoparticles 314 may include tin, lithium alloy, iron, silver, cobalt,semiconducting materials and/or metals such as silicon and/or the like.In some aspects, CNTs, due to their ability to provide high exposedsurface areas per unit volume and stability at relatively hightemperatures (such as above 77° F. or 25° C.), may be used as a supportmaterial for the first nanoparticles 314. For example, the firstnanoparticles 314 may be immobilized (such as by decoration, deposition,surface modification or the like) onto exposed surfaces of CNTs and/orother carbonaceous materials. The first nanoparticles 314 may react withchemically available carbon on exposed surfaces of the CNTs and/or othercarbonaceous materials.

The second thin film 320 may include a plurality of second aggregates322 that join together to form a second porous structure 326. In someinstances, the electrical conductivities of the first porous structure316 and/or the second porous structure 326 may be between approximately0 S/m and 250 S/m. In instances for which the first porous structure 316includes a higher concentration of aggregates than the second porousstructure 326, the first porous structure 316 may have a higherelectrical conductivity than the second porous structure 326. In oneimplementation, the first electrical conductivity may be betweenapproximately 250 S/m and 500 S/m, while the second electricalconductivity may be between approximately 100 S/m and 250 S/m. Inanother implementation, the second electrical conductivity may bebetween approximately 250 S/m and 500 S/m. In yet anotherimplementation, the second electrical conductivity may be greater than500 S/m. In some aspects, the second aggregates 322 may include CNTs,CNOs, flaky graphene, crinkled graphene, graphene grown on carbonaceousmaterials, and/or graphene grown on graphene.

The second aggregates 322 may be decorated with a plurality of secondnanoparticles 324. In some implementations, the second nanoparticles 324may include iron, silver, cobalt, semiconducting materials and/or metalssuch as silicon and/or the like. In some instances, CNTs may also beused as a support material for the second nanoparticles 324. Forexample, the second nanoparticles 324 may be immobilized (such as bydecoration, deposition, surface modification or the like) onto exposedsurfaces of CNTs and/or other carbonaceous materials. The secondnanoparticles 324 may react with chemically available carbon on exposedsurfaces of the CNTs and/or other carbonaceous materials.

In some aspects, the first thin film 310 and/or the second thin film 320(as well as any additional thin films disposed on their respectiveimmediately preceding thin film) may be created as a layer or region ofmaterial and/or aggregates. The layer or region may range from fractionsof a nanometer to several microns in thickness, such as betweenapproximately 0 and 5 microns, between approximately 5 and 10 microns,between approximately 10 and 15 microns, or greater than 15 microns. Anyof the materials and/or aggregates disclosed herein, such as CNOs, maybe incorporated into the first thin film 310 and/or the second thin film320 to result in the described thickness levels.

In some implementations, the first thin film 310 may be deposited ontothe second substrate 102 of FIG. 1 by chemical deposition, physicaldeposition, or grown layer-by-layer through techniques such as Frank-vander Merwe growth, Stranski-Krastonov growth, Volmer-Weber growth and/orthe like. In other implementations, the first thin film 310 may bedeposited onto the second substrate 102 by epitaxy or other suitablethin-film deposition process involving the epitaxial growth ofmaterials. The second thin film 320 and/or subsequent thin films may bedeposited onto their respective immediately preceding thin film in amanner similar to that described with reference to the first thin film310.

In various implementations, each of the first aggregates 312 and/or thesecond aggregates 322 may be a relatively large particle formed by manyrelatively small particles bonded or fused together. As a result, theexternal surface area of the relatively large particle may besignificantly smaller than combined surface areas of the many relativelysmall particles. The forces holding an aggregate together may be, forexample, covalent, ionic bonds, or other types of chemical bondsresulting from the sintering or complex physical entanglement of formerprimary particles.

As discussed above, the first aggregates 312 may join together to formthe first porous structure 316, and the second aggregates 322 may jointogether to form the second porous structure 326. The electricalconductivity of the first porous structure 316 may be based on theconcentration level of the first aggregates 312 within the first porousstructure 316, and the electrical conductivity of the second porousstructure 326 may be based on the concentration level of the secondaggregates 322 within the second porous structure 326. In some aspects,the concentration level of the first aggregates 312 may cause the firstporous structure 316 to have a relatively high electrical conductivity,and the concentration level of the second aggregates 322 may cause thesecond porous structure 326 to have a relatively low electricalconductivity (such that the first porous structure 316 has a greaterelectrical conductivity than the second porous structure 326). Theresulting differences in electrical conductivities of the first porousstructure 316 and the second porous structure 326 may create anelectrical conductivity gradient across the electrode 300. In someimplementations, the electrical conductivity gradient may be used tocontrol or adjust electrical conduction throughout the electrode 300and/or one or more operations of the battery 100 of FIG. 1.

As used herein, the relatively small source particles may be referred toas “primary particles,” and the relatively large aggregates formed bythe primary particles may be referred to as “secondary particles.” Asshown in FIG. 1, FIGS. 8 to 10, and elsewhere throughout the presentdisclosure, the primary particles may be or include multiple graphenesheets, layers, regions, and/or nanoplatelets fused and/or joinedtogether. Thus, in some instances, carbon nano-onions (CNOs), carbonnano-tubes (CNTs), and/or other tunable carbon materials may be used toform the primary particles. In some aspects, some aggregates may have aprincipal dimension (such as a length, a width, and/or a diameter)between approximately 500 nm and 25 μm. Also, some aggregates mayinclude innately-formed smaller collections of primary particles,referred to as “innate particles,” of graphene sheets, layers, regions,and/or nanoplatelets joined together at orthogonal angles. In someinstances, these innate particles may each have a respective dimensionbetween approximately 50 nm and 250 nm.

The surface area and/or porosity of these innate particles may beimparted by secondary processes, such as carbon-activation by a thermal,plasma, or combined thermal-plasma process using one or more of steam,hydrogen gas, carbon dioxide, oxygen, ozone, KOH, ZnCl₂, H₃PO₄, or othersimilar chemical agents alone or in combination. In someimplementations, the first porous structure 316 and/or the second porousstructure 326 may be produced from a carbonaceous gaseous species thatcan be controlled by gas-solid reactions under non-equilibriumconditions. Producing the first porous structure 316 and/or the secondporous structure 326 in this manner may involve recombination ofcarbon-containing radicals formed from the controlled cooling ofcarbon-containing plasma species (which can be generated by excitementor compaction of feedstock carbon-containing gaseous and/or plasmaspecies in a suitable chemical reactor).

In some implementations, the first aggregates 312 and/or the secondaggregates 322 may have a percentage of carbon to other elements, excepthydrogen, within each respective aggregate of greater than 99%. In someinstances, a median size of each aggregate may be between approximately0.1 microns and 50 microns. The first aggregates 312 and/or the secondaggregates 322 may also include metal organic frameworks (MOFs).

In some implementations, the first porous structure 316 and secondporous structure 326 may collectively define a host structure 328, forexample, as shown in FIG. 3. In some instances, the host structure 328may be based on a carbon scaffold and/or may include decorated carbons,for example, as shown in FIG. 8. The host structure 328 may providestructural definition to the electrode 300. In some instances, the hoststructure 328 may be fabricated as a positive electrode and used in thecathode 110 of FIG. 1. In other implementations, the host structure 328may be fabricated as a negative electrode and used in the anode 120 ofFIG. 1. In some other implementations, the host structure 328 mayinclude pores having different sizes, such as micropores, mesopores,and/or macropores defined by the IUPAC. In some instances, at least someof the micropores may have a width of approximately 1.5 nm, which may belarge enough to allow sulfur to be pre-loaded into the electrode 300 andyet small enough to confine polysulfides within the electrode 300.

The host structure 328, when provided within the electrode 300 as shownin FIG. 3, may include microporous, mesoporous, and/or macroporouspathways created by exposed surfaces and/or contours of the first porousstructure 316 and/or the second porous structure 326. These pathways mayallow the host structure 328 to receive an electrolyte, for example, bytransporting lithium cations (Li⁺) towards the cathode 110 of thebattery 100. Specifically, the electrolyte 130 may infiltrate thevarious porous pathways of the host structure 328 and uniformly dispersethroughout the electrode 300 and/or other portions of the battery 100.Infiltration of the electrolyte 130 into such regions of the hoststructure 328 may allow the lithium cations (Li⁺) 125 migrating from theanode 120 towards the cathode 110 to react with elemental sulfurassociated with the cathode 110 to form lithium-sulfur complexes. As aresult, the elemental sulfur may retain additional quantities of lithiumcations (Li⁺) that would otherwise be achievable using non-sulfurchemistries such as lithium cobalt oxide (LiCoO) or other lithium-ioncells.

In some aspects, each of the first porous structure 316 and/or thesecond porous structure 326 may have a porosity based on one or more ofa thermal, plasma, or combined thermal-plasma process using one or moreof steam, hydrogen gas, carbon dioxide, oxygen, ozone, KOH, ZnCl2,H3PO4, or other similar chemical agents alone or in combination. Forexample, in one implementation, the macroporous pathways may have aprincipal dimension greater than 50 nm, the mesoporous pathways may havea principal dimension between approximately 20 nm and 50 nm, and themicroporous pathways may have a principal dimension less than 4 nm. Assuch, the macroporous pathways and mesoporous pathways can providetunable conduits for transporting lithium cations (Li⁺) 125, and themicroporous pathways may confine active materials within the electrode300.

In some implementations, the electrode 300 may include one or moreadditional thin films (not shown for simplicity). Each of the one ormore additional thin films may include individual aggregatesinterconnected with each other across different thin films, with atleast some of the thin films having different concentration levels ofaggregates. As a result, the concentration levels of any thin film maybe varied (such as by gradation) to achieve particular electricalresistance (or conductance) values. For example, in someimplementations, the concentration levels of aggregates mayprogressively decline between the first thin film 310 and the last thinfilm (such as in a direction 195 depicted in FIG. 1), and/or theindividual thin films may have an average thickness betweenapproximately 10 microns and approximately 200 microns. In addition, orin the alternative, the first thin film 310 may have a relatively highconcentration of carbonaceous aggregates, and the second thin film 320may have a relatively low concentration of carbonaceous aggregates. Insome aspects, the relatively high concentration of aggregatescorresponds to a relatively low electrical resistance, and therelatively low concentration of aggregates corresponds to a relativelyhigh electrical resistance.

The host structure 328 may be prepared with multiple active sites onexposed surfaces of the first aggregates 312 and/or the secondaggregates 322. These active sites, as well as the exposed surfaces ofthe first aggregates 312 and/or the second aggregates 322, mayfacilitate ex-situ electrodeposition prior to incorporation of theelectrode 300 into the battery 100. Electroplating is a process that cancreate a lithium layer 330 (including lithium on exposed surfaces of thehost structure 328) through chemical reduction of metal cations byapplication and/or modulation of an electric current. In implementationsfor which the electrode 300 serves as the anode 120 of the battery 100in FIG. 1, the host structure 328 may be electroplated such that thelithium layer 330 has a thickness between approximately 1 and 5micrometers (μm), 5 μm and 20 μm, or greater than 20 μm. In someinstances, ex-situ electrodeposition may be performed at a locationseparate from the battery 100 prior to the assembly of the battery 100.

In various implementations, excess lithium provided by the lithium layer330 may increase the number of lithium cations (Li⁺) 125 available fortransport in the battery 100, thereby increasing the storage capacity,longevity, and performance of the battery 100 (as compared withtraditional lithium-ion and/or lithium-sulfur batteries).

In some aspects, the lithium layer 330 may produce lithium-intercalatedgraphite (LiC₆) and/or lithiated graphite based on chemical reactionswith the first aggregates 312 and/or the second aggregates 322. Lithiumintercalated between alternating graphene layers may migrate or betransported within the electrode 300 due to differences inelectrochemical gradients during operational cycling of the battery 100,which in turn may increase the energy storage and power delivery of thebattery 100.

FIG. 4 shows a diagram of a portion of an example battery 400 thatincludes a protective lattice 402, according to some implementations. Insome implementations, the protective lattice 402 may be disposed on theanode 220 of the battery 200. In other implementations, the protectivelattice 402 may be disposed on the cathode 210 of the battery 200 (orother suitable batteries). In some aspects, the protective lattice 402may be one example of the protective lattice 280 of FIG. 2. Theprotective lattice 402 may function with many components (e.g., anode,cathode, current collectors associated, carbonaceous materials,electrolyte, and separator) in a manner similar to the battery 100 ofFIG. 1 and/or the battery 200 of FIG. 2.

The protective lattice 402 may include a tri-functional epoxy compoundand a di-amine oligomer-based compound that can chemically react witheach other to produce a 3D lattice structure (e.g., as shown in FIG. 6and FIG. 8). In some aspects, the protective lattice 402 may preventpolysulfide migration within the battery 400 by providing nitrogen andoxygen atoms that can chemically bind with lithium present in thepolysulfides, thereby impeding the migration of polysulfides through theelectrolyte 130. As a result, lithium cations (Li⁺) 125 can be morefreely transported from the anode 120 and the cathode 110 of FIG. 1,thereby increasing battery performance metrics.

Cyclical usage of the cathode 110 may cause the formation of cracks 404that at least partially extend into the cathode 110. In oneimplementation, the protective lattice 402 may disperse throughout thecracks 404, thereby reducing susceptibility of the cathode 110 torupture during volumetric expansion of the cathode 110 caused by theretention of polysulfides within the cathode 110 during cyclical usage.In one implementation, the protective lattice 402 of FIG. 4 may have across-linked, 3D structure based on chemical reactions betweendi-functional, or higher functionality Epoxy and Amine or Amidecompounds. For example, the di-functional, or higher functionality Epoxycompound may be trimethylolpropane triglycidyl ether (TMPTE),tris(4-hydroxyphenyl)methane triglycidyl ether, or tris(2,3-epoxypropyl)isocyanurate, and di-functional, or higher functionality Amine compoundmay be dihydrazide sulfoxide (DHSO) or one of polyetheramines, forexample JEFFAMINE® D-230 characterized by repeating oxypropylene unitsin the backbone.

In various implementations, the chemical compounds may be combined andreacted with each other in any number of quantities, amounts, ratiosand/or compositions to achieve different performance capabilitiesrelating to binding with polysulfides generated during operation of thebattery 400. For example, in one implementation, 113 mg of TMPTE and 134mg of JEFFAMINE® D-230 polyetheramine may be mixed together and dilutedwith 1 mL to 10 mL of tetrahydrofuran (THF), or any other solvent.Additional amounts of TMPTE and/or JEFFAMINE may be mixed together anddiluted in THF, or any other solvent, at an example ratio of 113 mg ofTMPTE for every 134 mg of JEFFAMINE® D-230 polyetheramine. For thisimplementation, proof-of-concept (POC) data shows that the protectivelattice 402 of FIG. 4 has a defined weight of approximately 2.6 wt. % ofthe cathode 110 of FIG. 1 or the cathode 210 of FIG. 2. In otherimplementations, the protective lattice 402 may have a weight ofapproximately 2 wt. % to 21 wt. % of the cathode 110 and/or the cathode210, where an impedance increases of the cathode 110 and/or the cathode210 may be expected at a weight level of approximately 10 wt. % or morefor the protective lattice 402.

In various implementations, the protective lattice 402 may be fabricatedbased on a mole and/or molar ratio of —NH₂ group and epoxy groups andmay further accommodate various forms of cross-linking betweendi-functional, or higher functionality Epoxy and Amine or Amidecompound. In some aspects, such forms of cross-linking may include afully cross-linked stage, e.g., where one —NH₂ group is chemicallybonded with two epoxy groups and may further extend to configurationsincluding one NH₂ group chemically bonded with only one epoxy group.Still further, in one or more implementations, mixtures including excessquantities (above the ratios presented here) of —NH₂ groups may beprepared to provide additional polysulfide binding capability for theprotective lattice 402.

In some other implementations, the protective lattice 402 may beprepared by mixing 201 g of TMPTE with between 109 g and 283 g ofJEFFAMINE® D-230 polyetheramine. The resulting mixture may be thendiluted with 1 L to 20 L of a selected solvent (such as THF). Theresultant diluted solution may be deposited and/or otherwise disposed onthe cathode 110 to achieve a crosslinker content between 1 wt. % to 10wt. %. Additional TMPTE and/or JEFFAMINE may be mixed together anddiluted in THF, or another suitable solvent, at an example ratio of 201g of TMPTE for every 109 g to 283 g of JEFFAMINE® D-230 polyetheramine.

In still other implementations, the protective lattice 402 may beprepared by mixing 201 g of TMPTE with between 74 g and 278 g DHSO. Theresulting mixture may be then diluted with 1 L to 20 L of a selectedsolvent (such as THF). The resultant diluted solution may be depositedand/or otherwise disposed on the cathode 110 to achieve a crosslinkercontent between 1 wt. % to 10 wt. %. Additional TMPTE and/or JEFFAMINEmay be mixed together and diluted in THF, or another suitable solvent,at an example ratio of 201 g of TMPTE for every 201 g to 278 g ofJEFFAMINE® D-230 polyetheramine.

In one implementation, di-functional, or higher functionality Epoxycompound may chemically react with di-functional, or higherfunctionality amine compound to produce the protective lattice 402 in a3D cross-linked form, which may include both functional epoxy compoundsand amine containing molecules. In some aspects, the protective lattice402, when deposited on the cathode 110 of FIG. 1 or the cathode 210 ofFIG. 2, may have a thickness between approximately 1 nm and 5 μm.

In some implementations, the protective lattice 402 may increase thestructural integrity of the cathode 110 or the cathode 210, may reducesurface roughness, and may retain polysulfides in the cathode. Forexample, in one implementation, the protective lattice 402 may serve assheath on exposed surfaces of the cathode and bind with polysulfides toprevent their migration and diffusion into the electrolyte 130. In thisway, aspects of the subject matter disclosed herein may prevent (or atleast reduce) battery capacity decay by suppressing the polysulfideshuttle effect. In some aspects, the protective lattice 402 may alsofill the cracks 404 formed in the cathode of FIG. 4 to improve cathodecoating integrity. In various implementations, the protective lattice402 may be prepared by drop casting processes in the presence of asolvent, where the resultant solution can penetrate in cracks 404 of thecathode 110 and bind with polysulfides in the cathode 110 to preventtheir migration and/or diffusion throughout the electrolyte 130.

In various implementations, the protective lattice 402 may providenitrogen atoms and/or oxygen atoms that can chemically bond with lithiumin the polysulfides generated during operational battery cycling. In oneexample, the polysulfides may bond with available nitrogen atomsprovided by, for example, DHSO. In another example, the polysulfides maybond with available oxygen atoms provided by, for example, DHSO. In yetanother example, the polysulfides may bond with other available oxygenatoms.

In some other implementations, the recipes described above may bealtered by replacing TMPTE with a tris(4-hydroxyphenyl)methanetriglycidyl ether 910 and/or a tris(2,3-epoxypropyl) isocyanurate. Invarious implementations, the di-amine oligomer-based compound may be (ormay include) a JEFFAMINE® D-230, or other polyetheramines containingpolyether backbone normally based on either propylene oxide (PO),ethylene oxide (EO), or mixed PO/EO structure, for example JEFFAMINE®D-400, JEFFAMINE® T-403. The protective lattice 402 may also includevarious concentration levels of inert molecules, e.g., polyethyleneglycol chains of various lengths, which may allow to fine-tunemechanical properties of protective lattice and the chemical bonding ofvarious atoms to lithium present in the polysulfides.

FIG. 5 shows a diagram of an anode structure 500 that includes a tinfluoride (SnF₂) layer, according to some implementations. Specifically,the diagram depicts a cut-away schematic view of the anode structure 500in which all of the components associated with a first region A haveidentical counterparts in a second region B, where the first and secondregions A and B have opposite orientations around a current collector520. As such, the description below with reference to the components offirst region A is equally applicable to the components of second regionB. In some aspects, the anode 502 may be one example of the anode 120 ofFIG. 1 and/or the anode 220 of FIG. 2.

As discussed, lithium-sulfur batteries, such as the battery 100 of FIG.1 and the battery 200 of FIG. 2, operate as conversion-chemistry typeelectrochemical cells in that sulfur pre-loaded into the cathode maydissolve rapidly into the electrolyte prior to and during operation.Lithium, which may be provided by lithiated anodes and/or may beprevalent in the electrolyte, dissociates into lithium cations (Li⁺)suitable for transport from the anode to the cathode through theelectrolyte. The production of lithium cations (Li⁺) is associated witha corresponding release of electrons, which may flow through an externalcircuit to power a load, as described with reference to FIG. 1. However,when lithium dissociates into lithium cations (Li⁺) and electrons (e⁻),some of the lithium cations (Li⁺) may undesirably react withpolysulfides produced in the cathode, and therefore may no longer beavailable to generate an output current or voltage. This consumption oflithium cations (Li⁺) by polysulfides reduces the overall capacity ofthe host cell or battery, and may also facilitate corrosion of theanode, which can result in cell failure.

In some implementations, the protective layer 516 may be provided aspassivation coating that can reduce the chemical reactivity of the anode502 during cell assembly or formation. In some aspects, the protectivelayer 516 may be permeable to lithium cations (Li⁺) while concurrentlyprotecting the anode 502 from corrosion caused by chemical reactionsbetween lithium cations (Li⁺) and polysulfides. In otherimplementations, the protective layer 516 may be an artificialsolid-electrolyte interphase (A-SEI) that can replace naturallyoccurring SEIs and/or other types of conventional A-SEIs. In variousimplementations, the protective layer 516 may be deposited as a liner ontop of one or more films disposed on the anode 502. In some aspects, theprotective layer 516 may be a self-generating layer that forms duringelectrochemical reactions associated with operational cycling of thebattery. In some aspects, the protective layer 516 may have a thicknessthat is less than 5 microns. In other aspects, the protective layer 516may have a thickness between 0.1 and 1.0 microns.

In various implementations, one or more engineered additives that mayfacilitate the formation and/or deposition of the protective layer 516on the anode 502 may be provided within the electrolyte of the battery.In other implementations, the engineered additives may be an activeingredient of the protective layer 516. In some aspects, the protectivelayer 516 may provide tin ions and/or fluoride anions that can preventundesirable lithium growths from a first edge 5181 and a second edge5182 of the anode.

A graded layer 514 may be formed and/or deposited onto the anode 502beneath the protective layer 516. In various implementations, the gradedlayer 514 may prevent lithium contained in or associated with the anode502 from participating in undesirable chemical interactions and/orreactions with the electrolyte 540 that can lead to the growth oflithium-containing dendrites from the anode 502. The graded layer 514may also facilitate the production of lithium fluoride based on chemicalreactions between dissociated lithium cations (Li⁺) and fluoride ions.As discussed, the presence of lithium fluoride in or near the anode 502can decrease the polysulfide shuttle effect. For example, formation oflithium fluoride (e.g., form available lithium cations (Li⁺) andfluorine ions) may occur uniformly across the entirety of the first edge5181 and/or the second edge 5182 of the anode. In this way, localizedregions of high lithium concentration in the electrolyte 540 near theanode 502 are substantially inhibited. As a result, lithium-lithiumbonds contributing to the formation of lithium containing dendriticstructures extending length-wise from the anode are correspondinglyinhibited, thereby yielding free passage of lithium cations (Li⁺) fromthe anode 502 into the electrolyte (e.g., as encountered during batteryoperational cycling). In some aspects, the uniform distribution oflithium throughout the graded layer 514 can increase a uniformity of alithium-ion flux during battery operational cycling. In some aspects,the graded layer 514 may be approximately 5 nanometers (nm) inthickness.

In one or more implementations, the graded layer 514 may structurallyreinforce the host battery in a manner that not only decreases orprevents lithium-containing dendritic growth from the anode 502 but alsoincreases the ability of the anode 502 to expand and contract duringoperational cycling of the host battery without rupturing. In someaspects, the graded layer 514 has a 3D architecture with a gradedconcentration gradient (e.g., of one or more formative materials and/oringredients including carbon, tin, and/or fluorine), which facilitatesrapid lithium-ion transport. As a result, the graded layer 514 markedlyimproves overall battery efficiency and performance.

In some implementations, the graded layer 514 may provide anelectrochemically desirable surface upon which the protective layer 516may be grown or deposited. For example, in some aspects, the gradedlayer 514 may include compounds and/or organometallic compoundsincluding (but not limited to) aluminum, gallium, indium, nickel, zinc,chromium, vanadium, titanium, and/or other metals. In other aspects, thegraded layer 514 may include oxides, carbides and/or nitrides ofaluminum, gallium, indium, nickel, zinc, chromium, vanadium, titanium,and/or other metals.

In some implementations, the graded layer 514 may include carbonaceousmaterials including (but not limited to) flaky graphene, few layergraphene (FLG), carbon nano onions (CNOs), graphene nanoplatelets, orcarbon nanotubes (CNTs). In other implementations, the graded layer 514may include carbon, oxygen, hydrogen, tin, fluorine and/or othersuitable chemical compounds and/or molecules derived from tin fluorideand one or more carbonaceous materials. The graded layer 514 may beprepared and/or deposited either directly or indirectly on the anode 502at a different concentration levels. For example, the graded layer 514may include 5 wt. % carbonaceous materials with a balance of 95 wt. %tin fluoride, which may result in a relatively uniform disassociation offluorine atoms and/or fluoride anions from the tin fluoride.

Other suitable ratios include: 5% carbonaceous materials with 95% tinfluoride; 10% carbonaceous materials with 90% tin fluoride, 15%carbonaceous materials with 85% tin fluoride, 20% carbonaceous materialswith 80% tin fluoride, 25% carbonaceous materials with 75% tin fluoride,30% carbonaceous materials with 70% tin fluoride, 35% carbonaceousmaterials with 65% tin fluoride, 40% carbonaceous materials with 60% tinfluoride, 45% carbonaceous materials with 55% tin fluoride, 50%carbonaceous materials with 50% tin fluoride, 55% carbonaceous materialswith 45% tin fluoride, 55% carbonaceous materials with 45% tin fluoride,60% carbonaceous materials with 40% tin fluoride, 65% carbonaceousmaterials with 35% tin fluoride, 70% carbonaceous materials with 30% tinfluoride, 75% carbonaceous materials with 25% tin fluoride, 80%carbonaceous materials with 20% tin fluoride, 85% carbonaceous materialswith 15% tin fluoride, 90% carbonaceous materials with 10% tin fluoride,95% carbonaceous materials with 5% tin fluoride. The fluorine atomsand/or fluoride anions may then uniformly react and combine with lithiumcations (Li⁺) to form lithium fluoride, as further discussed below.

In some implementations, lithium cations (Li⁺) cycling between the anode502 and the cathode (not shown in FIG. 5) may produce a tin-lithiumalloy region 512 within the graded layer 514. In some aspects,operational cycling of the host battery may result in a uniformdispersion of lithium fluoride within the tin-lithium alloy region 512.The uniform dispersion of lithium fluoride may facilitate adefluorination reaction of at least some of tin (II) fluoride (SnF₂)within the tin fluoride layer 510 (and additional tin fluoride which mayhave dispersed into the graded layer 514 and/or the protective layer).The fluorine atoms and/or fluoride anions made available by thedefluorination reaction may chemically bond with at least some of thelithium cations (Li⁺) present in or near the anode 502, to createlithium fluoride (LiF) and correspondingly thereby prevent at least someof the lithium cations (Li⁺) from bonding with each other and creating alithium dendritic growth from the anode 502.

For example, at least a portion of the fluorine atoms and/or fluorideanions present in the tin fluoride may dissociate from the protectivelayer 516 and produce tin cations (Sn²⁺) and fluorine anions (2F⁻) viaone or more chemical reactions. The fluorine atoms and/or fluorideanions dissociated from the protective layer 516 may chemically bond toat least some of the lithium cations (Li⁺) present in the electrolyte540 and/or dispersed throughout the protective layer 516 or the gradedlayer 514. In some aspects, the dissociated fluorine atoms may form Li—Fbonds or Li—F compounds in the tin-lithium alloy region 512. In otheraspects, the dissociated fluorine atoms may form a tin fluoride layer510 within the graded layer 514.

In addition, in one implementation, at least some of the defluorinatedtin fluoride may disperse uniformly throughout the graded layer 514 toproduce lithium fluoride (LiF) crystals. The lithium fluoride crystalsmay act as an electrical insulator and prevent the flow of electronsfrom the anode 502 into the electrolyte 540 through the first edge 5181and/or the second edge 5182 of the anode 502.

In various implementations, the graded layer 514 may be deposited on theanode 502 by one or more of atomic layer deposition (ALD), chemicalvapor deposition (CVD), or physical vapor deposition (PVD). For example,ALD may be used to deposit protective films on the anode 502 such as,for example, an ALD film that at least partially reacts with theelectrolyte 540 during high-pressure bonding processes. Accordingly, theALD film may be used to produce the protective layer 516 or the gradedlayer 514 using an atomic plane available for lithium transfer. Suchlithium transfer may be similar in principle to that observed for fewlayer graphene (FLG) or graphite, where alternating graphene layers inFLG or graphite intercalate lithium cations (Li⁺) in various formsincluding as lithium titanium oxide (LTO), lithium iron phosphate (PO₃)(LFP). The described forms of intercalated lithium, e.g., LTO and/orLFP, may be oriented to facilitate rapid lithium atom and/or lithium iontransport and/or diffusion, which may be conducive for the formationand/or synthesis of lithium fluoride (e.g., in the tin fluoride layer510 and/or elsewhere), as described earlier. Additional forms ofintercalated lithium, e.g., perovskite lithium lanthanum titanate(LLTO), may also function to store lithium within the anode 502.

In some implementations, the graded layer 514 may include variousdistinct types and/or forms of carbon and/or carbonaceous materials,each having one or more physical attributes that can be selected orconfigured to adjust the reactivity of carbon with contaminants (such aspolysulfides) present in the electrolyte 540 and/or the anode 502. Insome aspects, the selectable physical attributes may include (but arenot limited to) porosity, surface area, surface functionalization, orelectric conductivity. In addition, the graded layer 514 may includebinders or other additives that can be used to adjust one or morephysical attributes of the carbonaceous materials to achieve a desiredreactivity of carbon supplied by the carbonaceous materials withpolysulfides present in the electrolyte 540 and/or the anode 502.

In one implementation, carbonaceous materials within the graded layer514 may capture unwanted contaminants and thereby prevent thecontaminants from chemically reacting with lithium available at exposedsurfaces of the anode 502. Instead, the unwanted contaminants (e.g.,polysulfides) may chemically react with various exposed surfaces of thecarbonaceous materials within the graded layer 514 (e.g., throughcarbon-lithium interactions). In some implementations, the carbonaceousmaterials within the graded layer 514 may cohere to the availablelithium. The degree of cohesion between the carbonaceous materials andthe lithium cations (Li⁺) may be selected or modified via chemicalreactions induced during preparation of the graded layer 514.

In some implementations, various carbon allotropes may be incorporatedwithin the graded layer 514 (such as in one or more portions of thetin-lithium alloy region 512 and/or the tin fluoride layer 510). Thesecarbon allotropes may be functionalized with one or more reactants andused to form a sealant layer and/or region at an interface of carbonnanodiamonds within the graded layer 514 and the electrolyte 540. Insome aspects, the carbon nanodiamonds may increase the mechanicalrobustness of the anode 502 and/or the graded layer 514. In otheraspects, the carbon nanodiamonds may also provide exposed carbonaceoussurfaces that may be used to decrease the polysulfide shuttle effect bymicro-confining and/or bonding with polysulfides present in theelectrolyte 540 in a manner that retains the polysulfides within definedregions of the battery external to the anode 502.

Alternatively, in other implementations, the carbon nanodiamonds withinthe graded layer 514 may be replaced with carbons and/or carbonaceousmaterials including surfaces and/or regions having a specific LAdimensions (e.g., sp² hybridized carbon), reduced graphene oxide (rGO),and/or graphene. In some aspects, employing the carbonaceous materialsdisclosed herein within a battery may increase carbon stacking and layerformation within the graded layer 514. Exfoliated and oxidizedcarbonaceous materials may also yield more uniform layered structureswithin the graded layer 514 (as compared to carbonaceous materials thathave not been exfoliated and oxidized). In some aspects, solvents suchas tetrabutylammonium hydroxide (TBA) and/or dimethyl formamide (DMF)treatments may be applied to the carbonaceous materials disclosed hereinto increase the wetting of exposed carbonaceous surfaces within thegraded layer 514.

In some implementations, slurries used to form the graded layer 514 maybe doped to improve or otherwise influence the crystalline structure ofcarbonaceous materials within the graded layer 514. For example,addition of certain dopants may influence the crystalline structure ofthe carbonaceous materials in a certain corresponding way, andfunctional groups may be added (e.g., via grafting onto exposed carbonatoms within the carbonaceous materials) within the graded layer 514.

In some implementations, carbonaceous materials having exposed surfacesfunctionalized with one or more of fluorine-containing orsilicon-containing functional groups may be included within the gradedlayer 514. In other implementations, carbonaceous materials havingexposed surfaces functionalized with one or more of fluorine-containingor silicon-containing functional groups may be deposited beneath thegraded layer 514 to form a stable SEI on at an interface between thegraded layer 514 and the anode 502. In one implementation, the stableSEI may replace the protective layer 516. In some implementations, thegraded layer 514 may be slurry cast and/or deposited using othertechniques onto the anode 502 with lithium and carbon interphases, anyof which may be functionalized with silicon and/or nitrogen to inhibitthe diffusion and migration of polysulfides towards exposed surfaces ofthe anode 502. In addition, specific polymers and/or crosslinkers may beincorporated within the graded layer 514 to mechanically strengthen thegraded layer 514, to improve lithium ion transport across the gradedlayer 514, or to increase the uniformity of lithium ion flux across thegraded layer 514. Example polymers and/or polymeric materials suitablefor incorporation within the graded layer 514 may include poly(ethyleneoxide) and poly(ethyleneimine). Example crosslinkers suitable forincorporation within the graded layer 514 may include inorganic linkers(e.g., borate, aluminate, silicate), multifunctional organic molecules(e.g., diamines, diols), polyurea, or high molecular weight (MW)(e.g., >10,000 daltons) carboxymethyl cellulose (CMC).

Various fabrication methods may be employed to produce the graded layer514. In one implementation, direct coating of the interface between theanode 502 and the electrolyte 540 prior to the deposition and/orformation of the graded layer 514 may be performed with a dispersion ofcarbonaceous materials and other chemicals dissolved in a carrier (e.g.,a solvent, binder, polymer). In another implementation, deposition ofthe graded layer 514 may be performed as a separate operation, or may beadded to various other active ingredients (e.g., metals, carbonaceousmaterials, tin fluoride and/or the like) into a slurry that can be castonto the anode 502. Alternatively, in another implementation, theprotective layer 516 may be transferred directly onto the anode 502 by acalendar roll lamination processes. The protective layer 516 and/or thegraded layer 514 may also incorporate partially-cured lithium ionconductive epoxies to, for example, increase adhesion with lithiumbetter during the calendar roll lamination processes.

In one implementation, a carbon-inclusive layered structure (not shownin FIG. 5) may be disposed on the anode 502 as a replacement for thegraded layer 514. The carbon-inclusive layered structure may include anatomic plane available for lithium transfer, and may uniformly transportlithium cations (Li⁺) provided by the electrolyte 540 throughout theprotective layer 516 in a manner that can guide the formation of lithiumfluoride in various portions of the battery. In various implementations,the carbon-inclusive layered structure may include one or morearrangements of few layer graphene (FLG) or graphite and/or mayintercalate with lithium and produce one or more reaction productsincluding lithium tin oxide (LTO), lithium iron phosphate (LFP), orperovskite lithium lanthanum titanate (LLTO).

In some implementations, the tin fluoride layer 510 may function as aprotection layer against corrosion, including corrosion ofcopper-inclusive surfaces and/or regions of the protective layer 516,the graded layer 514, or the anode 502. In some aspects, the tinfluoride layer 510 may also provide a uniform seed layer suitable forlithium deposition, and thereby inhibiting dendrite formation. Inaddition, in some implementations, the tin fluoride layer 510 mayinclude one or more lithium ion intercalating compounds, any one or morehaving a low voltage penalty. Suitable lithium ion intercalatingcompounds may include graphitic carbon (e.g., graphite, graphene,reduced graphene oxide, rGO). In one implementation, during fabricationof the anode 502, lithium cations (Li⁺) may tend to intercalate prior toplating onto exposed carbonaceous surfaces within the tin fluoride layer510. In this way, the tin fluoride layer 510 will have a uniform Lidistribution ready to act as a seed layer prior to initiation of lithiumplating and/or electroplating operations.

In one implementation, one or more conformal coatings may be appliedover portions of the anode 502 such that the resulting conformal coatingcontacts and conforms to the first edge 5181 and/or the second edge 5182of the anode 502. In some aspects, the conformal coating may begin as afirst spacer edge protection region 5301 and a second spacer edgeprotection region 5302 that react or otherwise combine with one or moreof the protective layer 516, the tin-lithium alloy region 512, and/orthe tin fluoride layer 510 to form a conformal coating 544 that at leastpartially seals and protects surfaces and/or interfaces between lithiumin the anode 502 and various substances suspended in the electrolyte,e.g., copper (Cu). In some aspects, the dissociation of fluorine atomsfrom tin fluoride present in the conformal coating 544 may react withlithium in the anode 502 to form lithium fluoride, rather than form orgrow into lithium dendrites. In this way, the conformal coating 544 maydecrease lithium dendrite formation or growth from the anode 502.

The conformal coating 544 may be deposited or disposed over the anode502 at any number of different thicknesses. In some aspects, theconformal coating 544 may be less than 5 μm thick. In other aspects, theconformal coating 544 may be less than 2 μm thick. In some otheraspects, the conformal coating 544 may be less than 1 μm thick. Thesethickness levels may impede the migration of polysulfides towards theanode 502 during battery cycling, thereby preventing at least some ofthe lithium cations (Li⁺) from reacting with the polysulfides. Lithiumcations (Li⁺) that do not react with the polysulfides are available fortransport from the anode to the cathode during discharge cycles of thebattery.

The conformal coating 544 (as well as the protective layer 516 and thegraded layer 514) can uniquely regulate lithium ion flux toward thefirst edge 5181 and/or the second edge 5182 of the anode 502, andthereby prevent corrosion of the anode 502. Such regulation may functionin a similar manner to gate spacers used during the fabrication ofpolysilicon (poly-Si) gates. Specifically, gate spacer or gate sidewallconstructs may be used to protect and mechanically support polysilicongates during the fabrication of integrated circuits (ICs). Similarly,edge protection provided by the conformal coating 544 for the anode 502of FIG. 5 regulates lithium ion flux toward the first edge 5181 and/orthe second edge 5182 of the anode 502, and thereby prevents corrosion ofthe anode 502. This type of edge protection provided by the conformalcoating 544 for the anode 502 may equally apply to other battery and/orelectrical cell formats and/or configurations such as (but not limitedto) cylindrical cells, stacked cells, and/or the like, with variousconstructs engineered specifically to fit within the parameters of eachof these designs.

In some implementations, fabrication and/or deposition of the conformalcoating 544, the protective layer 516, and/or the graded layer 514 onthe anode 502 may depend on the type of battery or cell construct inwhich the anode 502 is incorporated, e.g., cylindrical cells compared topouch cells and/or prismatic cells. In one implementation, forcylindrical cells, metal anodes may be constructed from an electroactivematerial, typically metallic lithium, and/or lithium-containing alloys,such as graphitic and/or other carbonaceous composited includinglithium, as well as any plenary uniform or multi-layer sheet ofmaterial. In one example, a solid metal lithium foil used as the anode502 may be attached to a copper substrate used as the current collector520 to facilitate electron transfer through a tab 546 to an externalload, as depicted in the example of FIG. 5. In other implementations,the anode structure 500 may include the anode 502 without the currentcollector 520, where carbonaceous materials contained within the anode502 may provide an electrically conductive medium coupled to a circuit.

In some implementations, the anode structure 500 may be incorporatedinto electrochemical cells and/or batteries by winding around a mandrel.Cylindrical cell layouts typically use double-sided anodes, such as theanode structure 500. In some implementations, cylindrical cellconstructions employing the anode structure 500 may use the conformalcoating 544 to protect the first edge 5181 and/or the second edge 5182of the anode 502. The uniform protection provided by the conformalcoating 544 may be referred to herein as “edge protection.” In oneimplementation, edge protection can be incorporated into a cellemploying the anode structure 500 by extending the size and/or area ofthe protective layer 516 to overlap beyond any geometrically inducededge effects, e.g., surface roughness, of the anode.

In other implementations, the anode structure 500 may be incorporatedinto pouch cells and/or prismatic cells. Generally, two constructs ofpouch and/or prismatic cells may be manufactured, including (1):jelly-roll type cells (e.g., seen in industry as lithium-polymerbatteries), two mandrel wound electrodes may be produced in a mannersimilar to cylindrical cells as discussed earlier; and (2): stackedplate type cells, which may be cut from a sheet of a pre-cast and/orpre-laminated prepared anode, leaving an unprotected edge of, forexample, the anode 502 (when prepared in a stacked-plate typeconfiguration) exposed and vulnerable to corrosion, fast ion fluxes andexposure within the cells. The conformal coating 544, in a stacked-platetype configuration, may protect the anode 502 and prevent lithiumover-saturation in the electrolyte 540. In this way, the conformalcoating 544 can control lithium plating on the anode 502 duringoperational cycling of the battery.

In some implementations, one or more chemical reactions may occurbetween the electrolyte 540 and the anode 502 (involving solventdecomposition and/or additive reactions) during cell assembly or cellrest period. These chemical reactions may assist in the production ofthe conformal coating 544. In some aspects, elevated and/or reducedtemperatures (e.g., relative to room temperature and/or 20° C.) may beused as a stimulus for lithium-induced polymerization of the conformalcoating 544. For example, the lithium-induced polymerization may occurin the presence of one or more catalysts and/or by using lithium metal,and its associated chemical reactivity, as an inducing agent to initiatefree-radical based polymerization of component species within any one ormore layers of the anode structure 500 and/or the conformal coating 544.In addition, electrochemical reactions under electrical bias in eitherthe forward or reverse direction may be used to fabricate and/or depositthe conformal coating 544 onto the anode 502, as well as usage ofsecondary metals and/or salts as additives that may decompose to form analloy on the first edge 5181 and/or the second edge 5182 of metalliclithium in the anode 502 exposed to the electrolyte 540. For example,suitable additives may contain one or more metallic species, e.g.,desired for co-alloying with lithium or to be used as a blocking layerto reduce lithium transfer to the first edge 5181 and/or the second edge5182 of the anode 502.

FIG. 6 shows a schematic diagram of an enlarged portion 600 of the anodestructure 500 of FIG. 5, according to some implementations. The enlargedportion 600 illustrates placement of the first spacer edge protectionregion 5301 and the second spacer edge protection region 5302(collectively referred to as the edge protection region 530 in FIG. 6)in a direction orthogonal to the first edge 5181 and/or the second edge5182, as shown in FIG. 5. As a result, the edge protection region 530,which may include the carbonaceous materials 610 organized intostructures and/or lattices, may block lithium cations (Li⁺) fromundesirably escaping the anode 502 across the edge protection region530. In this way, lithium ion dissociation, flux, transport, and/orother movement may be channeled effectively throughout the enlargedportion 600 of FIG. 6 (as well as the anode structure 500 of FIG. 5),thereby yielding optimal battery operational cycling. In someimplementations, carbonaceous materials 610 used to produce the edgeprotection region may include few layer graphene (FLG), multi-layergraphene (MLG), graphite, carbon nano-tubes (CNTs), carbon nano-onions(CNOs) and/or the like. The carbonaceous materials 610 (e.g., shown inFIG. 8A, FIG. 8B, FIG. 9A, FIG. 9B, FIG. 10A and/or FIG. 10B) may besynthesized, self-nucleated, or otherwise joined together at varyingconcentration levels to provide for complete tunability of the edgeprotection region 530. For example, the density, thickness, and/orcompositions of may be designed to reduce lithium ion permeation morethan the protective layer 516 or the graded layer 514 to direct lithiumion permeation accordingly. In some implementations, the edge protectionregion 530 may be less than 5 μm thick. In other aspects, the edgeprotection region 530 may be less than 2 μm thick. In some otheraspects, the edge protection region 530 may be less than 1 μm thick. Insome implementations, a conductive additive 640 may be added to thecarbonaceous materials 610, as well as a binder 620.

FIG. 7 shows a diagram of a polymeric network 710, according to someimplementations. In some aspects, the polymeric network 710 may be oneexample of the polymeric network 285 of FIG. 2. The polymeric network710 may be disposed on an anode 702. The anode 702 may be formed as analkali metal layer having one or more exposed surfaces that include anynumber of alkali metal-containing nanostructures or microstructures. Thealkali metal may include (but is not limited to) lithium, sodium, zinc,indium and/or gallium. The anode 702 may release alkali cations duringoperational cycling of the battery.

A layer 714 of carbonaceous materials may be grafted with fluorinatedpolymer chains and deposited over one or more exposed surfaces of theanode 702. The grafting may be based on (e.g., initiated by) activationof carbonaceous material with one or more radical initiators, forexample, benzoyl peroxide (BPO) or azobisisobutyronitrile (AIBN),followed by reaction with monomer molecules. The polymeric network 710may be based on the fluorinated polymer chains cross-linked with oneanother and carbonaceous materials of the layer 714 such that the layer714 is consumed during generation of the polymeric network 710. In someimplementations, the polymeric network 710 may have a thicknessapproximately between 0.001 μm and 5 μm and include betweenapproximately 0.001 wt. % to 2 wt. % of the fluorinated polymer chains.In some other implementations, the polymeric network 710 may includebetween approximately 5 wt. % to 100 wt. % of the plurality ofcarbonaceous materials grafted with fluorinated polymer chains and abalance of fluorinated polymers, or one or more non-fluorinatedpolymers, or one or more cross-linkable monomers, or combinationsthereof. In one implementation, carbonaceous materials grafted withfluorinated polymer chains may include 5 wt. % to 50 wt. % offluorinated polymer chains and a balance of carbonaceous material.

During battery cycling, carbon-fluorine bonds within the polymericnetwork 710 may chemically react with newly forming Lithium metal andconvert into carbon-Lithium bonds (C—Li). These C—Li bonds may, in turn,react with carbon-fluorine bonds within the polymeric network 710 via aWurtz reaction 750, to further cross-link polymeric network by newlyformed C—C bonds and to form an alkali-metal containing fluoride (suchas lithium fluoride (LiF)). Additional polymeric network cross-linkingleading to uniform formation of the alkali-metal containing fluoride maythereby suppress alkali metal dendrite formation 740 associated with theanode 702, thereby improving battery performance and longevity. In oneimplementation, grafting of fluorinated m/acrylate (FMA) to one or moreexposed graphene surfaces of carbonaceous materials in the layer 714 maybe performed in an organic solution, e.g., leading to the formation ofgraphene-graft-poly-FMA and/or the like. Incorporation ofcarbon-fluorine bonds on exposed graphene surfaces may enable the Wurtzreaction 750 to occur between carbon-fluorine bonds and metallic surfaceof an alkali metal (e.g., lithium) provided by the anode 702. In thisway, completion of the Wurtz reaction 750 may result in the formation ofthe polymeric network 710. In some aspects, the polymeric network 710may include a density gradient 716 pursuant to completion of the Wurtzreaction 750. The density gradient 716 may include interconnectedgraphene flakes and may be infused with one or more metal-fluoride saltsformed in-situ. In addition, layer porosity and/or mechanical propertiesmay be tuned by carbon loading and/or a combination of functionalizedcarbons, each having a unique and/or distinct physical structure.

In some implementations, carbonaceous materials within the densitygradient 716 may include one or more of flat graphene, wrinkledgraphene, a plurality of carbon nano-tubes (CNTs), or a plurality ofcarbon nano-onions (CNOs) (e.g., as depicted in FIG. 8A and/FIG. 8B andas shown in the micrographs of FIGS. 9A-9B and FIGS. 10A-10B). In oneimplementation, graphene nanoplatelets may be dispersed throughout andisolated from each other within the polymeric network 710. Thedispersion of the graphene nanoplatelets includes one or more differentconcentration levels. In one implementation, the dispersion of thegraphene nanoplatelets may include at least some of the carbonaceousmaterials functionalized with at least some of the fluorinated polymerchains.

For example, the fluorinated polymer chains may include one or moreacrylate or methacrylate monomers including2,2,3,3,4,4,5,5,6,6,7,7-Dodecafluoroheptyl acrylate (DFHA),3,3,4,4,5,5,6,6,7,7,8,8,9,9,10,10,10-Heptadecafluorodecyl methacrylate(HDFDMA), 2,2,3,3,4,4,5,5-Octafluoropentyl methacrylate (OFPMA),Tetrafluoropropyl methacrylate (TFPM),3-[3,3,3-Trifluoro-2-hydroxy-2-(trifluoromethyl)propyl]bicyclo[2.2.1]hept-2-ylmethacrylate (HFA monomer), or vinyl-based monomers including2,3,4,5,6-Pentafluorostyrene (PFSt).

In some implementations, fluorinated polymer chains may be grafted to asurface of the layer of carbonaceous materials and may therebychemically interact with the one or more surfaces of the alkali metal ofthe anode via the Wurtz reaction 750. In organic chemistry,organometallic chemistry, and inorganic main-group polymers, the Wurtzreaction is a coupling reaction, whereby two alkyl halides are reactedwith sodium metal (or some other metal) in dry ether solution to form ahigher alkane. In this reaction alkyl halides are treated with alkalimetal, for example, sodium metal in dry ethereal (free from moisture)solution to produce higher alkanes. In case of Sodium intermediateproduct of the Wurtz reaction are highly polar and highly reactiveCarbon-Sodium metal bonds, which in turn are chemically reacting withCarbon-Halide bonds to yield newly formed C—C bonds and Sodium Halide. Aformation of new Carbon-Carbon bonds allows to use the Wurtz reactionfor the preparation of higher alkanes containing even number of carbonatoms, for example:

$\begin{matrix}\left. {{2R - X} + {2Na}}\rightarrow{{R - R} + {2{Na}^{+}X^{-}}} \right. & \left( {{Eq}.1} \right)\end{matrix}$

Other metals have also been used to influence Wurtz coupling, among themsilver, zinc, iron, activated copper, indium and a mixture of manganeseand copper chloride. The related reaction dealing with aryl halides iscalled the Wurtz-Fittig reaction. This can be explained by the formationof free radical intermediate and its subsequent disproportionation togive alkene. The Wurtz reaction 750 occurs through a free-radicalmechanism that makes possible side reactions producing alkene products.In some implementations, chemical interactions associated with the Wurtzreaction described above may form an alkali metal fluoride, e.g.,lithium fluoride.

In one implementation, the polymeric network 710 may include aninterface layer 718 in contact with the anode 702. A protective layer720 may be disposed on top of the interface layer 718, which may bebased on the Wurtz reaction 750 at an interface between the anode 702and the polymeric network 710. The interface layer 718 may have arelatively high cross-linking density (e.g., of fluorinated polymersand/or the like), a high metal-fluoride concentration, and a relativelylow carbon-fluorine bond concentration. In contrast to the interfacelayer 718, the protective layer 720 may have a relatively lowcross-linking density, a low metal-fluoride concentration, and a highcarbon-fluorine bond concentration.

In some implementations, the interface layer 718 may includecross-linkable monomers such as methacrylate (MA), acrylate, vinylfunctional groups, or a combination of epoxy and amine functionalgroups. In one implementation, the protective layer 720 may becharacterized by the density gradient 716. In this way, the densitygradient 716 may be associated with one or more self-healing propertiesof the protective layer 720 and/or may strengthen the polymeric network710. In some implementations, the protective layer 720 may furthersuppress alkali metal dendrite formation 740 from the anode 702 duringbattery cycling.

Operationally, the interface layer 718 may suppress alkali metaldendrite formation 740 associated with the anode 702 by uniformlyproducing metal-fluorides, e.g., lithium fluoride, at an interfaceacross the length of the anode 702. The uniform production of metalfluorides causes dendrite surface dissolution, e.g., via conversion intometal-fluorides, ultimately suppressing alkali metal dendrite formation740. In addition, cross-linking of fluorinated polymer chains overremaining dendrites may further suppress alkali metal dendrite formation740. In some implementations, the density gradient 716 may be tuned tocontrol the degree of cross-linking between the fluorinated polymerchains.

FIG. 8A shows a simplified cutaway view of an example carbonaceousparticle 800 with graded porosity, according to some implementations.The carbonaceous particle 800 may be synthesized in a reactor, andoutput in a controlled manner to produce the cathode 110 and/or anode120 of FIG. 1, the cathode 210 and/or anode 220 of FIG. 2, or theelectrode 300 of FIG. 3. The carbonaceous particle 800, which may alsobe referred to as a composition of matter, includes a plurality ofregions nested within each other. Each region may include at least afirst porosity region 811 and a second porosity region 812. The firstporosity region 811 may include a plurality of first pores 801, and thesecond porosity region 812 may include a plurality of second pores 802.In some aspects, each region may be separated from immediate adjacentregions by at least some of the first pores 801. The first pores 801 maybe dispersed throughout the first porosity region 811 of thecarbonaceous particle 800, and the second pores 802 may be dispersedthroughout the second porosity region 812 of the carbonaceous particle800. In this way, the first pores 801 may be associated with a firstpore density, and the second pores 802 may be associated with a secondpore density that is different than the first pore density. In someaspects, the first pore density may be between approximately 0.0 cubiccentimeters (cc)/g and 2.0 cc/g, and the second pore density may bebetween approximately 1.5 and 5.0 cc/g. In some aspects, the first pores801 may be configured to retain polysulfides 820, and the second pores802 may provide exit pathways from the carbonaceous particle 800.

A group of carbonaceous particles 800 may be joined together to form acarbonaceous aggregate (not shown for simplicity), and a group ofcarbonaceous aggregates may be joined together to form a carbonaceousagglomerate (not shown for simplicity). In some implementations, thefirst pores 801 and second pores 802 may be dispersed throughoutaggregates formed by respective groups of the carbonaceous particles800. In some aspects, the first porosity region 811 may be at leastpartially encapsulated by the second porosity region 812 such that arespective agglomerate may include some of the first pores 801 and/orsome of the second pores 802.

In some implementations, the carbonaceous particle 800 may have aprincipal dimension “A” in an approximate range between 20 nm and 150nm, an aggregate formed by a group of the carbonaceous particle 800 mayhave a principal dimension in an approximate range between 20 nm and 10μm, and an agglomerate formed by a group of aggregates may have aprincipal dimension in an approximate range between 0.1 μm and 1,000 μm.In some aspects, at least some of the first pores 801 and the secondpores 802 has a principal dimension in an approximate range between 1.3nm and 32.3 nm. In one implementation, each of the first pores 801 has aprincipal dimension in an approximate range between 0 nm and 100 nm.

The carbonaceous particle 800 may also include a plurality of deformableregions 813 distributed along a perimeter 810 of the carbonaceousparticle 800. The carbonaceous particle 800 may conduct electricityalong joined boundaries with (such as the perimeter 810) one or moreother carbonaceous particles. The carbonaceous particle 800 may alsoconfine polysulfides 820 within the first pores 801 and/or at one ormore blocking regions 822, thereby inhibiting the migration ofpolysulfides 820 towards the anode and increasing the rate at whichlithium cations (Li⁺) can be transported from the anode to the cathodeof a host battery.

In some implementations, the carbonaceous particle 800 may have asurface area of exposed carbon surfaces in an approximate range between10 m²/g to 3,000 m²/g. In other implementations, the carbonaceousparticle 800 may have a composite surface area including sulfur 824micro-confined within a number of the first pores 801 and/or a number ofthe second pores 802. As used herein, the first pores 801 and/or thesecond pores 802 that micro-confine the polysulfides 820 may be referredto as “functional pores.” In some aspects, one or more of thecarbonaceous particles, the aggregates formed by corresponding groups ofcarbonaceous particles, or the agglomerates formed by correspondinggroups of aggregates may include one or more exposed carbon surfacesconfigured to nucleate the sulfur 824. The composite surface area may bein an approximate range between 10 m²/g to 3,000 m²/g, and thecarbonaceous particle 800 may have a sulfur to carbon weight ratiobetween approximately 1:5 to 10:1. In some aspects, the carbonaceousparticle 800 may have an electrical conductivity in an approximate rangebetween 100 S/m to 20,000 S/m at a pressure of 12,000 pounds per squarein (psi).

In some implementations, the carbonaceous particle 800 may include asurfactant or a polymer that includes one or more of styrene butadienerubber, polyvinylidene fluoride, poly acrylic acid, carboxyl methylcellulose, polyvinylpyrrolidone, and/or polyvinyl acetate that can actas a binder to join a group of the carbonaceous particles 800 together.In other implementations, the carbonaceous particle 800 may include agel-phase electrolyte or a solid-phase electrolyte disposed within atleast some of the first pores 801 or second pores 802.

FIG. 8B shows a diagram of an example of a tri-zone particle 850,according to some implementations. In various implementations, thetri-zone particle 850 may be one example of the carbonaceous particle800 of FIG. 8A. The tri-zone particle 850 may include three discretezones such as (but not limited to) a first zone 851, a second zone 852,and a third zone 853. In some aspects, each of the zones 851-853surrounds and/or encapsulates a preceding zone. For example, the firstzone 851 may be surrounded by or encapsulated by the second zone 852,and the second zone 852 may be surrounded by or encapsulated by thethird zone 853. The first zone 851 may correspond to an inner region ofthe tri-zone particle 850, the second zone 852 may correspond to anintermediate transition region of the tri-zone particle 850, and thethird zone 853 may correspond to an outer region of the tri-zoneparticle 850. In some aspects, the tri-zone particle 850 may include apermeable shell 855 that deforms in response to contact with one or moreadjacent non-tri-zone particles and/or tri-zone particles 850.

In some implementations, the first zone 851 may have a relatively lowdensity, a relatively low electrical conductivity, and a relatively highporosity, the second zone 852 may have an intermediate density, anintermediate electrical conductivity, and an intermediate porosity, andthe third zone 853 may have a relatively high density, a relatively highelectrical conductivity, and a relatively low porosity. In some aspects,the first zone 851 may have a density of carbonaceous material betweenapproximately 1.5 g/cc and 5.0 g/cc, the second zone 852 may have adensity of carbonaceous material between approximately 0.5 g/cc and 3.0g/cc, and the third zone 853 may have a density of carbonaceous materialbetween approximately 0.0 and 1.5 g/cc. In other aspects, the first zone851 may include pores having a width between approximately 0 and 40 nm,the second zone 852 may include pores having a width betweenapproximately 0 and 35 nm, and the third zone 853 may include poreshaving a width between approximately 0 and 30 nm. In some otherimplementations, the second zone 852 may not be defined for the tri-zoneparticle 850. In one implementation, the first zone 851 may have aprincipal dimension D₁ between approximately 0 nm and 100 nm, the secondzone 852 may have a principal dimension D₂ between approximately 20 nmand 150 nm, and the third zone 853 may have a principal dimension D₃ ofapproximately 200 nm.

Aspects of the present disclosure recognize that the unique layout ofthe tri-zone particle 850 and the relative dimensions, porosities, andelectrical conductivities of the first zone 851, the second zone 852,and the third zone 853 can be selected and/or modified achieve a desiredbalance between minimizing the polysulfide shuttle effect and maximizingthe specific capacity of a host battery. Specifically, in some aspects,the pores may decrease in size and volume from one zone to other. Insome implementations, the tri-zone particle may consist entirely of onezone with a range of pore sizes and pores distributions (e.g., poredensity). For the example of FIG. 8B, the Pores 861 associated with thefirst zone 851 or the first porosity region have relatively large widthsand may be defined as macropores, the pores 862 associated with thesecond zone 852 or the second porosity region have intermediate-sizedwidths and may be defined as mesopores, and the pores 863 associatedwith the third zone 853 or the third porosity region have relativelysmall widths and may be defined as micropores.

A group of tri-zone particles 850 may be joined together to form anaggregate (not shown for simplicity), and a group of the aggregates maybe joined together to form an agglomerate (not shown for simplicity). Insome implementations, a plurality of mesopores may be interspersedthroughout the aggregates formed by respective groups of thecarbonaceous particles 800. In some aspects, the first porosity region811 may be at least partially encapsulated by the second porosity region812 such that a respective aggregate may include one or more mesoporesand one or more macropores. In one implementation, each mesopore mayhave a principal dimension between 3.3 nanometers (nm) and 19.3 nm, andeach macropore may have a principal dimension between 0.1 μm and 1,000μm. In some instances, the tri-zone particle 850 may include carbonfragments intertwined with each other and separated from one another byat least some of the mesopores.

In some implementations, the tri-zone particle 850 may include asurfactant or a polymer that includes one or more of styrene butadienerubber, polyvinylidene fluoride, poly acrylic acid, carboxyl methylcellulose, polyvinylpyrrolidone, and/or polyvinyl acetate that can actas a binder to join a group of the carbonaceous materials together. Inother implementations, the tri-zone particle 850 may include a gel-phaseelectrolyte or a solid-phase electrolyte disposed within at least someof the pores.

In some implementations, the tri-zone particle 850 may have a surfacearea of exposed carbonaceous surfaces in an approximate range between 10m²/g to 3,000 m²/g and/or a composite surface area (including sulfurmicro-confined within pores) in an approximate range between 10 m²/g to3,000 m²/g. In one implementation, a composition of matter including amultitude of tri-zone particles 850 may have an electrical conductivityin an approximate range between 100 S/m to 20,000 S/m at a pressure of12,000 pounds per square in (psi) and a sulfur to carbon weight ratiobetween approximately 1:5 to 10:1.

FIG. 8C shows an example step function 800C representative of theaverage pore volumes in each of the regions of the tri-zone particle 850of FIG. 8B, according to some implementations. As discussed, the poresdistributed throughout the tri-zone particle 850 may have differentsizes, volumes, or distributions. In some implementations, the averagepore volume may decrease based on a distance between a center of thetri-zone particle 850 and an adjacent zonae, for example, such thatpores associated with the first zone 851 or the first porosity regionhave a relatively large volume or pore size, pores associated with thesecond zone 852 or the second porosity region have an intermediatevolume, and pores associated with the third zone 853 or the thirdporosity region have a relatively small volume. The interior region hasa higher pore volume than the regions near the periphery. The regionwith higher pore volume provides for high sulfur loading whereas thelower pore volume outer regions mitigate the migration of polysulfidesduring cell cycling. In the example of FIG. 8C, the average pore volumein the inner region is approximately 3 cc/g, the average pore volume inthe outermost region is −0.5 cc/g and the average pore volume in theintermediate region is between 0.5 cc/g and 3 cc/g.

FIG. 8D shows a graph 800D depicting an example distribution of porevolume versus pore width of carbonaceous particles described herein. Asdepicted in the graph 800D, pores associated with a relatively high porevolume may have a relatively low pore width, for example, such that thepore width generally increases as the pore volume decreases. In someaspects, pores having a pore width less than approximately 1.0 nm may bereferred to as micropores, pores having a pore width betweenapproximately 3 and 11 nm may be referred to as mesopores, and poreshaving a pore width greater than approximately 24 nm may be referred toas macropores.

FIG. 9A shows a micrograph 900 of a plurality of carbonaceous structures902, according to some implementations. In some implementations, each ofthe carbonaceous structures 902 may have a substantially hollow a coreregion surrounded by various monolithic carbon growths and/or layering.In some aspects, the monolithic carbon growths and/or layering may beexamples of the monolithic carbon growths and/or layering described withreference to FIGS. 8A and 8B. In some instances, the carbonaceousstructures 902 may include several concentric multi-layered fullerenesand/or similarly shaped carbonaceous structures organized at varyinglevels of density and/or concentration. For example, the actual finalshape, size, and graphene configuration of each of the carbonaceousstructures 902 may depend on various manufacturing processes. Thecarbonaceous structures 902 may, in some aspects, demonstrate poor watersolubility. As such, in some implementations, non-covalentfunctionalization may be utilized to alter one or more dispersibilityproperties of the carbonaceous structures 902 without affecting theintrinsic properties of the underlying carbon nanomaterial. In someaspects, the underlying carbon nanomaterial may be formative a sp²carbon nanomaterial. In some implementations, each of the carbonaceousstructures 902 may have a diameter between approximately 20 and 500 nm.In various implementations, groups of the carbonaceous structures 902may coalesce and/or join together to form the aggregates 904. Inaddition, groups of the aggregates 904 may coalesce and/or join togetherto form the agglomerates 906. In some aspects, one or more of thecarbonaceous structures 902, the aggregates 904, and/or the agglomerates906 may be used to form the anode and/or the cathode of the battery 100of FIG. 1, the battery 200 of FIG. 2, or the electrode 300 of FIG. 3.

FIG. 9B shows a micrograph 950 of an aggregate formed of carbonaceousmaterial, according to some implementations. In some implementations,the aggregate 960 may be an example of one of the aggregates 904 of FIG.9A. In one implementation, exterior carbonaceous shell-type structures952 may fuse together with carbons provided by other carbonaceousshell-type structures 954 to form a carbonaceous structure 956. A groupof the carbonaceous structures 956 may coalesce and/or join with oneanother to form the aggregate 1010. In some aspects, a core region 958of each of the carbonaceous structures 956 may be tunable, for example,in that the core region 958 may include various defined concentrationlevels of interconnected graphene structures, as described withreference to FIG. 8A and/or FIG. 8B. In some implementations, some ofthe carbonaceous structures 956 may have a first concentration ofinterconnected carbons approximately between 0.1 g/cc and 2.3 g/cc at ornear the exterior carbonaceous shell-type structure 952. Each of thecarbonaceous structures 956 may have pores to transport lithium cations(Li⁺) extending inwardly from toward the core region 1008.

In some implementations, the pores in each of the carbonaceousstructures 956 may have a width or dimension between approximately 0.0nm and 0.5 nm, between approximately 0.0 and 0.1 nm, betweenapproximately 0.0 and 6.0 nm, or between approximately 0.0 and 35 nm.Each carbonaceous structures 956 may also have a second concentration ator near the core region 958 that is different than the firstconcentration. For example, the second concentration may include severalrelatively lower-density carbonaceous regions arranged concentrically.In one implementation, the second concentration may be lower than thefirst concentration at between approximately 0.0 g/cc and 1.0 g/cc orbetween approximately 1.0 g/cc and 1.5 g/cc. In some aspects, therelationship between the first concentration and the secondconcentration may be used to achieve a balance between confining sulfuror polysulfides within a respective electrode and maximizing thetransport of lithium cations (Li⁺). For example, sulfur and/orpolysulfides may travel through the first concentration and be at leasttemporarily confined within and/or interspersed throughout the secondconcentration during operational cycling of a lithium-sulfur battery.

In some implementations, at least some of the carbonaceous structures956 may include CNO oxides organized as a monolithic and/orinterconnected growths and be produced in a thermal reactor. Forexample, the carbonaceous structures 956 may be decorated with cobaltnanoparticles according to the following example recipe: cobalt(II)acetate (C₄H₆CoO₄), the cobalt salt of acetic acid (often found astetrahydrate Co(CH₃CO₂)₂. 4 H₂O, which may be abbreviated as Co(Oac)₂. 4H₂O, may be flowed into the thermal reactor at a ratio of approximately59.60 wt % corresponding to 40.40 wt % carbon (referring to carbon inCNO form), resulting in the functionalization of active sites on the CNOoxides with cobalt, showing cobalt-decorated CNOs at a 15,000× level,respectively. In some implementations, suitable gas mixtures used toproduce Carbon #29 and/or the cobalt-decorated CNOs may include thefollowing steps:

-   -   Ar purge 0.75 standard cubic feet per minute (scfm) for 30 min;    -   Ar purge changed to 0.25 scfm for run;    -   temperature increase: 25° C. to 300° C. 20 mins; and    -   temperature increase: 300°-500° C. 15 mins.

Carbonaceous materials described with reference to FIGS. 9A and 9B mayinclude or otherwise be formed from one or more instances of graphene,which may include a single layer of carbon atoms with each atom bound tothree neighbors in a honeycomb structure. The single layer may be adiscrete material restricted in one dimension, such as within or at asurface of a condensed phase. For example, graphene may grow outwardlyonly in the x and y planes (and not in the z plane). In this way,graphene may be a two-dimensional (2D) material, including one orseveral layers with the atoms in each layer strongly bonded (such as bya plurality of carbon-carbon bonds) to neighboring atoms in the samelayer.

In some implementations, graphene nanoplatelets (e.g., formativestructures included in each of the carbonaceous structures 956) mayinclude multiple instances of graphene, such as a first graphene layer,a second graphene layer, and a third graphene layer, all stacked on topof each other in a vertical direction. Each of the graphenenanoplatelets, which may be referred to as a GNP, may have a thicknessbetween 1 nm and 3 nm, and may have lateral dimensions ranging fromapproximately 100 nm to 100 μm. In some implementations, graphenenanoplatelets may be produced by multiple plasma spray torches arrangedsequentially by roll-to-roll (R2R) production. In some aspects, R2Rproduction may include deposition upon a continuous substrate that isprocessed as a rolled sheet, including transfer of 2D material(s) to aseparate substrate. In some instances, the R2R production may be used toform the first thin film 310 and/or the second thin film 320 of theelectrode 300 of FIG. 3, for example, such that the concentration levelof the first aggregates 312 within the first thin film 310 is differentthan the concentration level of the second aggregates 322 within thesecond thin film 320. That is, the plasma spray torches used in the R2Rprocesses may spray carbonaceous materials at different concentrationlevels to create the first thin film 310 and/or the second thin film 320using specific concentration levels of graphene nanoplatelets.Therefore, R2R processes may provide a fine level of tunability for thebattery 100 of FIG. 1 and/or the battery 200 or FIG. 2.

FIGS. 10A and 10B show transmission electron microscope (TEM) images1000 and 1050, respectively, of carbonaceous particles treated withcarbon dioxide (CO₂), according to some implementations. Thecarbonaceous particles shown in FIGS. 10A and 10B may include orotherwise be formed from one or more instances of graphene, which mayinclude a single layer of carbon atoms with each atom bound to threeneighbors in a honeycomb structure.

FIG. 11 shows a diagram 1100 depicting carbon porosity types of variouscarbonaceous aggregates, according to some implementations. In variousimplementations, the carbonaceous aggregates described with reference toFIG. 11 may be examples of the aggregates 904 of FIG. 9A and/or thecarbonaceous structures 956 of FIG. 9B. In some aspects, thecarbonaceous aggregates described with reference to FIG. 11 may be usedto form the electrode 300 of FIG. 3. As discussed, the aggregates may beformed from or may include a group of carbonaceous structures such asthe carbonaceous structure 902 of FIG. 9A or the carbonaceous structures956 of FIG. 9B. In some aspects, the carbonaceous structures may beCNOs.

The carbonaceous structures may be used to form an electrode (such asthe electrode 300 of FIG. 3) having any of the porosity types shown inthe diagram 1100. For example, the electrode may include any of aporosity type 1 1110, a porosity type II 1120, and a porosity type III1130. In some implementations, the porosity type 1 1110 may include afirst pore 1111, a second pore 1112, and a third pore 1113, all sizedwith a principal dimension of less than 5 nm to retain polysulfideswithin the electrode. Some polysulfides may grow in size upon forminglarger complexes and become immovably lodged within pores of theporosity type I 1110. In some implementations, aggregates may be joinedtogether to create pores of the porosity type II 1120 and/or porositytype III 1130 that can retain larger polysulfides and/or polysulfidecomplexes.

FIG. 12 shows a graph 1200 depicting pore size versus pore distributionof an example electrode, according to some implementations. As usedherein, “Carbon 1” refers to structured carbonaceous materials includingmostly micropores (such as less than 5 nm in principal dimension), and“Carbon 2” refers to structured carbonaceous materials including mostlymesopores (such as between approximately 20 nm to 50 nm in principaldimension). In some implementations, an electrode suitable for use inone of the batteries disclosed herein may be prepared to have the poresize versus pore distribution depicted in the graph 1200.

FIG. 13 shows a first graph 1300 and a second graph 1310 depictingbattery performance per cycle number, according to some implementations.Specifically, the first graph 1300 shows the specific discharge capacityof an example battery employing an electrolyte 1302 disclosed hereinrelative to the specific discharge capacity of a conventional batteryemploying a conventional electrolyte. The second graph shows thecapacity retention of the battery employing the electrolyte 1302relative to the capacity retention of the battery employing theconventional electrolyte. In some aspects, the electrolyte 1302 may beone example of the electrolyte 130 of FIG. 1 or the electrolyte 230 ofFIG. 2. In the first graph 1300 and the second graph 1310, theconventional electrolyte is prepared as 1 M LiTFSI in DME:DOL:TEGDME(volume:volume:volume=1:1:1) with 2 wt. % LiNO₃.

FIG. 14 shows a bar chart 1400 depicting battery performance per cyclenumber, according to some implementations. Specifically, the bar chart1400 depicts the specific discharge capacity per cycle number of anexample battery employing an electrolyte 1402 disclosed herein relativeto the specific discharge capacity per cycle number of a conventionalbattery employing a conventional electrolyte. In some aspects, theelectrolyte 1402 may be one example of the electrolyte 130 of FIG. 1 orthe electrolyte 230 of FIG. 2. In the bar chart 1400, the conventionalelectrolyte is prepared as 1 M LiTFSI in DME:DOL:TEGDME(volume:volume:volume=1:1:1). The bar chart 1400 shows that employingthe electrolyte 1402 in an example battery (such as the battery 100 ofFIG. 1 or the battery 200 of FIG. 2) may increase the specific dischargecapacity of the battery by approximately 28% at the 3^(rd) cycle number,by approximately 30% at the 50^(th) cycle number, and by approximately39% at the 60^(th) as compared to a battery employing the conventionalelectrolyte.

FIG. 15 shows a first graph 1500 and a second graph 1510 depictingbattery performance per cycle number, according to some implementations.Specifically, the first graph 1500 shows the electrode dischargecapacity per cycle number of an example lithium-sulfur coin cellemploying an electrolyte 1502 disclosed herein relative to the electrodedischarge capacity per cycle number of an example lithium-sulfur coincell battery employing a conventional electrolyte, and the second graph1510 shows the capacity retention per cycle number of the lithium-sulfurcoin cell battery employing the electrolyte 1502 relative to theelectrode discharge capacity per cycle number of the lithium-sulfur coincell battery employing the conventional electrolyte. In some aspects,the electrolyte 1502 may be one example of the electrolyte 130 of FIG. 1or the electrolyte 230 of FIG. 2. The lithium-sulfur coin cell batteryis cycled at a discharge rate of 1C (such as fully discharged within onehour), at 100% depth-of-discharge (DOD) and is kept at approximately atroom temperature (68° F. or 20° C.). The conventional electrolyte isprepared as 1 M LiTFSI in DME:DOL:TEGDME (volume:volume:volume=1:1:1)with 2 wt. % LiNO₃.

FIG. 16 shows a graph 1600 depicting electrode discharge capacity percycle number, according to some implementations. Specifically, the graph1600 depicts the electrode discharge capacity per cycle number of anexample battery employing an electrolyte 1602 disclosed herein relativeto the electrode discharge capacity of a conventional battery employinga conventional electrolyte. In some aspects, the electrolyte 1602 may beone example of the electrolyte 130 of FIG. 1 or the electrolyte 230 ofFIG. 2. The conventional electrolyte is prepared as 1 M LiTFSI inDME:DOL:TEGDME (volume:volume:volume=1:1:1) with 2 wt. % LiNO₃, and theelectrolyte 1602 is prepared as 1 M LiTFSI in DME:DOL:TEGDME(volume:volume:volume=58:29:13) with approximately 2 wt. % LiNO₃.

FIG. 17 shows another graph 1700 depicting electrode discharge capacityper cycle number, according to some implementations. Specifically, thegraph 1700 depicts the electrode discharge capacity per cycle number ofan example battery employing an electrolyte 1702 and solvent package1704 disclosed herein relative to the electrode discharge capacity of aconventional battery employing a conventional electrolyte and solventpackage. The conventional electrolyte is prepared as 1 M LiTFSI inDME:DOL:TEGDME (volume:volume:volume=1:1:1) with approximately 2 wt. %LiNO₃, and the electrolyte 1702 is prepared as 1 M LiTFSI inDME:DOL:TEGDME (volume:volume:volume=58:29:13) with 2 wt. % LiNO₃.

The conventional solvent package is prepared as 1 M LiTFSI inDME:DOL:TEGDME (volume: volume:volume=1:1:1), and the solvent package1704 is prepared as 1 M LiTFSI in DME:DOL:TEGDME(volume:volume:volume=58:29:13).

FIG. 18 shows a graph 1800 depicting specific discharge capacity percycle number for various TBT-containing electrolyte mixtures, accordingto some implementations. As shown in the graph 1800, “181” indicates anelectrolyte without any TBT additions, resulting in a 0 M TBTconcentration level, “181-25TBT” indicates an electrolyte prepared at a25 M TBT concentration level and so on and so forth. In someimplementations, a 5M TBT concentration level may result in anapproximate 70 mAh/g discharge capacity increase relative to theelectrolyte without any TBT additions.

FIG. 19 shows a first graph 1900 depicting electrode discharge capacityper cycle number and a second graph 1910 depicting electrode capacityretention per cycle number, according to some implementations.Specifically, the first graph 1900 depicts the electrode dischargecapacity per cycle number of an example battery that includes aprotective lattice disclosed herein relative to the electrode dischargecapacity of an example battery that does not include the protectivelattice disclosed herein. The second graph 1910 depicts the electrodecapacity retention per cycle number of an example battery that includesthe protective lattice disclosed herein relative to the electrodecapacity retention of an example battery that does not include theprotective lattice disclosed herein. In some aspects, the protectivelattice may be one example of the protective lattice 402 of FIG. 4.Performance results for both the first graph 1900 and the second graph1910 include usage of an electrolyte prepared with 1 M LiTFSI inDME:DOL:TEGDME (volume:volume:volume=58:29:13) with 2 wt. % LiNO₃.

FIG. 20 shows a first graph 2000 depicting electrode discharge capacityper cycle number and a second graph 2010 depicting electrode capacityretention per cycle number, according to other implementations.Specifically, the first graph 2000 depicts the electrode dischargecapacity per cycle number of an example battery that includes thepolymeric network of FIG. 7. The second graph 2010 depicts the dischargecapacity retention per cycle number of an example battery that includesthe polymeric network of FIG. 7. The battery may be one example of thebattery 100 of FIG. 1 or the battery 200 of FIG. 2. Performance resultsfor both the first graph 2000 and the second graph 2010 include usage ofan electrolyte prepared with 1 M LiTFSI in DME:DOL:TEGDME(volume:volume:volume=58:29:13) with 2 wt. % LiNO₃.

FIG. 21 shows a first graph 2100 depicting electrode discharge capacityper cycle number and a second graph 2110 depicting electrode capacityretention per cycle number, according to some other implementations.Specifically, the first graph 2100 depicts the electrode dischargecapacity per cycle number of an example battery that includes theprotective layer 516 of FIG. 5. The second graph 2110 depicts thedischarge capacity retention per cycle number of an example battery thatincludes the protective layer 516 of FIG. 5. The battery may be oneexample of the battery 100 of FIG. 1 or the battery 200 of FIG. 2.Performance results for both the first graph 1900 and the second graph1910 include usage of an electrolyte prepared with 1 M LiTFSI inDME:DOL:TEGDME (volume:volume:volume=58:29:13) with 2 wt. % LiNO₃.

FIG. 22 shows an example cathode 2200 having a body 2201 and a width2205, according to some implementations. In some implementations, thecathode 2200 may be one example of the electrode 300 of FIG. 3. Thecathode 2200 may be similar to the electrode 300 of FIG. 3 in manyrespects, such that description of like elements is not repeated herein.In one implementation, the cathode 2200 includes a first porouscarbonaceous region 2210 and a second porous carbonaceous region 2220positioned adjacent to the first porous carbonaceous region 2210. Thefirst porous carbonaceous region 2210 may be formed of a firstconcentration level of carbonaceous materials, and the second porouscarbonaceous region 2220 formed of a second concentration level ofcarbonaceous materials dissimilar to the first concentration level ofcarbonaceous materials. For example, the second porous carbonaceousregion 2220 may have a lower concentration level of carbonaceousmaterials than the first porous carbonaceous region 2210 as shown inFIG. 22. In some aspects, additional porous carbonaceous regions (notshown in FIG. 22 for simplicity) maybe coupled with at least the secondporous carbonaceous region.

Specifically, these additional porous carbonaceous regions may bearranged in order of incrementally decreasing concentration levels ofcarbonaceous materials in a direction away from the first porouscarbonaceous region 2210 to provide for complete ionic transport andelectrical current tunability. That is, in one implementation, thesecond porous carbonaceous region 2220 may face a bulk electrolyte(e.g., provided in the liquid phase) and the first porous carbonaceousregion 2210 of the cathode 2200 may be coupled with a current collector(not shown in FIG. 22 for simplicity). In this way, denser carbonaceousregions, such as the first porous carbonaceous region 2210, mayfacilitate higher levels of electrical conduction (shown in FIG. 22 as“e′”) between adjacent contact points of carbonaceous materials, whilesparser carbonaceous regions, such as the second porous carbonaceousregion 2220, may facilitate higher levels of lithium ion transportassociated with improved lithium-sulfur battery discharge-charge cyclingrelative to conventional lithium ion batteries. In some implementations,additional carbonaceous regions coupled with and positioned adjacent tothe second porous carbonaceous region 2220 may have a lower density ofcarbonaceous materials than the second porous carbonaceous region 2220.In this way, the additional carbonaceous regions of lower density mayaccommodate higher levels of lithium ion transport to, for example,permit for tuning of various performance characteristics of theelectrode 300.

In one implementation, the first porous carbonaceous region 2210 mayinclude first non-tri-zone particles 2211. The configuration of thefirst non-tri-zone particles 2211 within the first porous carbonaceousregion is one example configuration. Other placements, orientations,alignments and/or the like are possible for the non-tri-zone particles.In some aspects, each non-tri-zone particle may be an example of one ormore carbonaceous materials disclosed elsewhere in the presentdisclosure. The first porous carbonaceous region 2210 may also includefirst tri-zone particles 2212 interspersed throughout the firstnon-tri-zone particles 2211 as shown in FIG. 22, or positioned in anyother placement, orientation, or configuration. Each first tri-zoneparticle 2212 may be one example of the tri-zone particle 850 of FIG.8B. In addition, or the alternative, each first tri-zone-particle 2212may include first carbon fragments 2213 intertwined with each other andseparated from one another by mesopores 2214. Each tri-zone-particle mayhave a first deformable perimeter 2215 configured to coalesce withadjacent first non-tri-zone particles 2211 and/or first tri-zoneparticles 2212.

The first porous carbonaceous region 2210 may also include firstaggregates 2216, where each aggregate includes a multitude of the firsttri-zone particles 2212 joined together. In one or more particularexamples, each first aggregate may have a principal dimension in a rangebetween 10 nanometers (nm) and 10 micrometers (μm). The mesopores 2214may be interspersed throughout the first plurality of aggregates, whereeach mesopore has a principal dimension between 3.3 nanometers (nm) and19.3 nm. In addition, the first porous carbonaceous region 2210 mayinclude first agglomerates 2217, where each agglomerate includes amultitude of the first aggregates 2216 joined to each other. In someaspects, each first agglomerate 2217 may have a principal dimension inan approximate range between 0.1 μm and 1,000 μm. Macropores 2218 may beinterspersed throughout the first aggregates 2216, where each macroporemay have a principal dimension between 0.1 μm and 1,000 μm. In someimplementations, one or more of the above-discussed carbonaceousmaterials, allotropes and/or structures may be one or more examples ofthat shown in FIGS. 9A and 9B.

The second porous carbonaceous may include second non-tri-zone particles2221, which may be one example of the first non-tri-zone particles 2211.The second porous carbonaceous region 2220 may include second tri-zoneparticles 2222, which may each be one example of each of the firsttri-zone particles 2212 and/or may be one example of the tri-zoneparticle 850 of FIG. 8B. In addition, or the alternative, each secondtri-zone particle 2222 may include second carbon fragments 2223intertwined with each other and separated from one another by themesopores 2214. Each second tri-zone particle 2222 may have a seconddeformable perimeter 2225 configured to coalesce with one or moreadjacent second non-tri-zone particles 2221 or second tri-zone particles2222.

In addition, the second porous carbonaceous region 2220 may includesecond aggregates 2226, where each second aggregate 2226 may include amultitude of the second tri-zone particles 2222 joined together. In oneor more particular examples, each second aggregate 2226 may have aprincipal dimension in a range between 10 nanometers (nm) and 10micrometers (μm). The mesopores 2214 may be interspersed throughout thesecond aggregates 2226, each mesopore may have a principal dimensionbetween 3.3 nanometers (nm) and 19.3 nm. Further, the second porouscarbonaceous region 2220 may include second agglomerates 2227, eachsecond agglomerate 2227 may include a multitude of the second aggregates2226 joined to each other, where each agglomerate may have a principaldimension in an approximate range between 0.1 μm and 1,000 μm. Themacropores 2218 may be interspersed throughout the second plurality ofaggregates, where each macropore having a principal dimension between0.1 μm and 1,000 μm. In some implementations, one or more of theabove-discussed carbonaceous materials, allotropes and/or structures maybe one or more examples of that shown in FIGS. 9A and 9B.

In one implementation, the first porous carbonaceous region 2210 and/orthe second porous carbonaceous region 2220 may include a selectivelypermeable shell (not shown in FIG. 22 for simplicity), which may form aseparated liquid phase on the first porous carbonaceous region 2210 orthe second porous carbonaceous region 2220, respectively. Anelectrolyte, such as any of the electrolytes disclosed in the presentdisclosure, may be dispersed within the first porous carbonaceous regionand/or the second porous carbonaceous region for lithium ion transportassociated with lithium-sulfur battery discharge-charge operationalcycling.

In one or more particular examples, the first porous carbonaceous region2210 may have an electrical conductivity in an approximate range between500 S/m to 20,000 S/m at a pressure of 12,000 pounds per square in(psi). The second porous carbonaceous region 2220 may have an electricalconductivity in an approximate range between 0 S/m to 500 S/m at apressure of 12,000 pounds per square in (psi). The first agglomerates2217 and/or second agglomerates 2227 may include aggregates connected toeach other with one or more polymer-based binders.

In some aspects, each first tri-zone particle 2212 may have a firstporosity region (not shown in FIG. 22 for simplicity) located around acenter of the first tri-zone particle 2212. Similarly, each secondtri-zone particle 2222 may have a first porosity region (not shown inFIG. 22 for simplicity) located around a center of the second tri-zoneparticle 2222. The first porosity region may include first pores. Asecond porosity region (not shown in FIG. 22 for simplicity) maysurround the first porosity region. The second porosity region mayinclude second pores. In one implementation, the first pores may definea first pore density, and the second pores may define a second poredensity that is different the first pore density.

In some aspects, the mesopores 2214 may be grouped into first mesoporesand second mesopores (both not shown in FIG. 22 for simplicity). In oneor more particular examples, the first mesopores may have a firstmesopore density, and the second mesopores may have a second mesoporedensity that is different than the first mesopore density. In addition,the macropores 2218 may be grouped into first macropores that may have afirst pore density, and second macropores (both not shown in FIG. 22 forsimplicity) that may have a second pore density different than the firstpore density.

In one implementation, the first porous carbonaceous region 2210 and/orthe second porous carbonaceous region 2220 may nucleate sulfur, such asthat necessary to facilitate operational discharge-charge cycling of anyof the lithium-sulfur batteries disclosed by the present disclosure. Forexample, the cathode 2200 may have a sulfur to carbon weight ratiobetween approximately 1:5 to 10:1. In some aspects, one or moreelectrically conductive additives may be dispersed within the firstporous carbonaceous region 2210 and/or the second porous carbonaceousregion 2220 to, for example, correspondingly influence discharge-chargecycling performance of the cathode 2200. In addition, a protectivesheath, such as the protective lattice 402 of FIG. 4, may be disposed onthe cathode.

In one implementation, the example cathode 2200 of FIG. 22 and/or any ofthe battery configurations presented in the present disclosure (such asthe battery 100 and/or 200), may be prepared with an electrolyte (suchas the electrolyte 130 and/or 230) dispersed throughout the respectivebattery configuration. In addition, or the alternative, the electrolyte130, the electrolyte 230 and/or the like may be formulated according tothe following numbered examples:

Example 1 A 0.4 molar (M) solution of lithiumbis(trifluoromethanesulfonyl)imide (LiTFSI) is prepared fromapproximately 114.83 grams of powdered LiTFSI dissolved in 1 liter of aliquid solvent mixture. The liquid solvent mixture (alternativelyreferred to as a “ternary solvent package”) has a 58:28:13 volume ratioof dimethoxyethane (DME), 1,3-dioxolane (DOL), and tetraethylene glycoldimethyl ether (TEGDME). An additive including 26 grams of lithiumnitrate (LiNO₃) is added to the 0.4 molar (M) solution of LiTFSI toachieve a dilution level of 2 percent by weight of lithium nitrate(LiNO₃). Example 2 A 0.4 molar (M) solution of LiTFSI is prepared fromapproximately 114.83 grams of powdered LiTFSI dissolved in 1 liter of aliquid solvent mixture having a 50:25:25 volume ratio of DME, DOL, andtetrahydrofuran (THF). An additive including 26 grams of lithium nitrate(LiNO₃) is added to the 0.4 molar (M) solution of LiTFSI to achieve adilution level of 2 percent by weight of lithium nitrate (LiNO₃).Example 3 A 0.4 molar (M) solution of LiTFSI is prepared fromapproximately 114.83 grams of powdered LiTFSI dissolved in 1 liter of aliquid solvent mixture having a 50:25:25 volume ratio of DME, DOL, andtoluene. An additive including 26 grams of lithium nitrate (LiNO3) isadded to the 0.4 molar (M) solution of LiTFSI to achieve a dilutionlevel of 2 percent by weight of lithium nitrate (LiNO3). Example 4 A 0.4molar (M) solution of LiTFSI is prepared from approximately 114.83 gramsof powdered LiTFSI dissolved in 1 liter of a liquid solvent mixturehaving a 50:25:25 volume ratio of DME, DOL, and dimethyl sulfoxide(DMSO). An additive including 26 grams of lithium nitrate (LiNO₃) isadded to the 0.4 molar (M) solution of LiTFSI to achieve a dilutionlevel of 2 percent by weight of lithium nitrate (LiNO₃). Example 5 A 0.4molar (M) solution of LiTFSI is prepared from approximately 114.83 gramsof powdered LiTFSI dissolved in 1 liter of a liquid solvent mixturehaving a 50:25:25 volume ratio of DME, DOL, and tetramethyl urea (TMU).An additive including 26 grams of lithium nitrate (LiNO₃) is added tothe 0.4 molar (M) solution of LiTFSI to achieve a dilution level of 2percent by weight of lithium nitrate (LiNO₃). Example 6 A 0.4 molar (M)solution of LiTFSI is prepared from approximately 114.83 grams ofpowdered LiTFSI dissolved in 1 liter of a liquid solvent mixture havinga 50:25:25 volume ratio of DME, DOL, and dimethyl formamide (DMF). Anadditive including 26 grams of lithium nitrate (LiNO₃) is added to the0.4 molar (M) solution of LiTFSI to achieve a dilution level of 2percent by weight of lithium nitrate (LiNO₃). Example 7 A 0.4 molar (M)solution of LiTFSI is prepared from approximately 114.83 grams ofpowdered LiTFSI dissolved in 1 liter of a liquid solvent mixture havinga 50:25:25 volume ratio of DME, DOL, and methoxyperfluorobutane (MPB).An additive including 26 grams of lithium nitrate (LiNO₃) may be addedto the 0.4 molar (M) solution of LiTFSI to achieve a dilution level of 2percent by weight of lithium nitrate (LiNO₃). Example 8 A 0.4 molar (M)solution of LiTFSI is prepared from approximately 114.83 grams ofpowdered LiTFSI dissolved in 1 liter of a liquid solvent mixture havinga 50:25:25 volume ratio of DME, DOL, and trifluoro ethyl ether (TFE). Anadditive including 26 grams of lithium nitrate (LiNO₃) is added to the0.4 molar (M) solution of LiTFSI to achieve a dilution level of 2percent by weight of lithium nitrate (LiNO₃). Example 9 A 0.4 molar (M)solution of LiTFSI is prepared from approximately 114.83 grams ofpowdered LiTFSI dissolved in 1 liter of a liquid solvent mixture havinga 50:25:25 volume ratio of DME, DOL, and triethylene glycol dimethylether (TrigDME). An additive including 26 grams of lithium nitrate(LiNO₃) is added to the 0.4 molar (M) solution of LiTFSI to achieve adilution level of 2 percent by weight of lithium nitrate (LiNO₃).Example 10 A 0.4 molar (M) solution of LiTFSI is prepared fromapproximately 114.83 grams of powdered LiTFSI dissolved in 1 liter of aliquid solvent mixture having a 50:25:25 volume ratio of DME, DOL, andmethyl tert-butyl ether (MTBE). An additive including 26 grams oflithium nitrate (LiNO₃) is added to the 0.4 molar (M) solution of LiTFSIto achieve a dilution level of 2 percent by weight of lithium nitrate(LiNO₃). Example 11 A 0.4 molar (M) solution of LiTFSI is prepared fromapproximately 114.83 grams of powdered LiTFSI dissolved in 1 liter of aliquid solvent mixture having a 50:25:25 volume ratio of DME, DOL, anddimethyl trisulfide (DMTS). An additive including 26 grams of lithiumnitrate (LiNO₃) is added to the 0.4 molar (M) solution of LiTFSI toachieve a dilution level of 2 percent by weight of lithium nitrate(LiNO₃). Example 12 A 0.4 molar (M) solution of LiTFSI is prepared fromapproximately 114.83 grams of powdered LiTFSI dissolved in 1 liter of aliquid solvent mixture having a 50:25:25 volume ratio of DME, DOL, andacetonitrile (can). An additive including 26 grams of lithium nitrate(LiNO₃) is added to the 0.4 molar (M) solution of LiTFSI to achieve adilution level of 2 percent by weight of lithium nitrate (LiNO₃).Example 13 A 0.4 molar (M) solution of LiTFSI is prepared fromapproximately 114.83 grams of powdered LiTFSI dissolved in 1 liter of aliquid solvent mixture having a 50:25:25 volume ratio of DME, DOL, and1,1,2,2-tetrafluoro-1- 1(2,2,2-trifluoroethoxy)ethane (TFETFE). Anadditive including 26 grams of lithium nitrate (LiNO₃) is added to the0.4 molar (M) solution of LiTFSI to achieve a dilution level of 2percent by weight of lithium nitrate (LiNO₃). Example 14 A 0.4 molar (M)solution of LiTFSI is prepared from approximately 114.83 grams ofpowdered LiTFSI dissolved in 1 liter of a liquid solvent mixture havinga 50:25:25 volume ratio of DME, DOL, and DAP. An additive including 26grams of lithium nitrate (LiNO₃) is added to the 0.4 molar (M) solutionof LiTFSI to achieve a dilution level of 2 percent by weight of lithiumnitrate (LiNO₃). Example 15 A 0.4 molar (M) solution of LiTFSI isprepared from approximately 114.83 grams of powdered LiTFSI dissolved in1 liter of a liquid solvent mixture having a 50:25:25 volume ratio ofDME, DOL, and TTE. An additive including 26 grams of lithium nitrate(LiNO₃) is added to the 0.4 molar (M) solution of LiTFSI to achieve adilution level of 2 percent by weight of lithium nitrate (LiNO₃).Example 16 A 0.4 molar (M) solution of LiTFSI is prepared fromapproximately 114.83 grams of powdered LiTFSI dissolved in 1 liter of aliquid solvent mixture having a 50:25:25 volume ratio of DME, DOL, and2-Methyltetrahydrofuran (MeTHF). An additive including 26 grams oflithium nitrate (L1NO3) is added to the 0.4 molar (M) solution of LiTFSIto achieve a dilution level of 2 percent by weight of lithium nitrate(LiNO₃). Example 17 A 0.4 molar (M) solution of LiTFSI is prepared fromapproximately 114.83 grams of powdered LiTFSI dissolved in 1 liter of aliquid solvent mixture having a 50:25:25 volume ratio of DME, DOL, andbis(2-methoxyethyl) ether (DEGDME). An additive including 26 grams oflithium nitrate (LiNO₃) is added to the 0.4 molar (M) solution of LiTFSIto achieve a dilution level of 2 percent by weight of lithium nitrate(LiNO₃). Example 18 A 0.1 molar (M) solution of LiTFSI is prepared fromapproximately 28.71 grams of powdered LiTFSI dissolved in 1 liter of aliquid solvent mixture having a 95:5 volume ratio of DME and DOL. Noadditional lithium nitrate (LiNO₃) is added to the 0.1 molar (M)solution of LiTFSI. Example 19 A 0.1 molar (M) solution of LiTFSI isprepared from approximately 28.71 grams of powdered LiTFSI dissolved in1 liter of a liquid solvent mixture having a 50:25:25 volume ratio ofDME, DOL, and bis(2-methoxyethyl) ether (DEGDME). An additive including26 grams of lithium nitrate (LiNO₃) is added to the 0.1 molar (M)solution of LiTFSI to achieve a dilution level of 2 percent by weight oflithium nitrate (LiNO₃). Example 20 A 0.4 molar (M) solution of LiTFSIis prepared from approximately 114.83 grams of powdered LiTFSI dissolvedin 1 liter of a liquid solvent mixture having a 58:29:13 volume ratio ofDME, DOL, and tetraethylene glycol dimethyl ether (TEGDME). Noadditional lithium nitrate (LiNO₃) is added to the 0.1 molar (M)solution of LiTFSI.

In some aspects, ionic conductivity of the lithium cations (Li⁺) 125transported throughout the electrolyte 130, such as when preparedaccording to any one or more of the above-presented examples, may dependon the molecular structure of various component substances of theelectrolyte 130. For example, substances that are hydrophobic and lesspolar may have lower ionic conductivity values. Substances that arehydrophilic and more polar may have higher ionic conductivity values. Inthis way, component materials used in the above electrolyte formulationexamples of the electrolyte 130 may be ranked from lowest ionicconductivity to highest ionic conductivity according to the followingorder: DMTS, TOL, TFETFE, MPB, MTBE, TrigDME, THF, TEE, TMU, DMSO, DMF,ACN.

Of the electrolyte components disclosed above in examples 1-20, lithiumnitrate (LiNO₃) may dissociate into lithium cations (Li⁺) (Li⁺) andnitrate anions (NO₃ ⁻). In this way, the lithium nitrate (LiNO₃) mayproduce nitrogen-oxygen containing compounds (not shown in the Figuresfor simplicity), which may be derived from and/or based on nitrateanions (NO₃ ⁻). The electrolyte 130, such as when prepared according toany one or more of the examples presented above, may prevent diffusionof nitrogen-oxygen containing compounds generated during operationaldischarge-charge cycling of the battery 100. In addition, some nitrateanions (NO₃ ⁻) may form a solvation sheath (not shown in the Figures forsimplicity) on the anode 120. In this way, the electrolyte 130 may beprepared to permit nitrogen-oxygen additives to coat the anode 120 atleast partially and thereby prevent the extension of dendrites from theanode 120 toward the cathode 110 through the electrolyte 130. Thesolvation sheath may form coordination complexes between LiTFSI in theelectrolyte 130 and the lithium cations (Li⁺) 125. The coordinationcomplexes may include a central atom or ion (such as the lithium cations(Li⁺) 125), which may be metallic and may be referred to as “thecoordination center,” and a surrounding array of bound molecules orions, which may be referred to ligands or complexing agents.

Protection against dendrite formation provided by the solvation sheathmay be at least partially compromised due to continued reduction ofnitrogen compounds prevalent in the nitrogen-oxygen additives that form,for example, nitrite (NO₂ ⁻), which may produce gas resulting in pocketsof gas bubbles in the electrolyte 130. These gas bubbles may interferewith transport of the lithium cations (Li⁺) 125, may cause expansion ofthe battery 100 and may also lead to undesirable hindrance of lithiumionic transport. To address these limitations, Example 18 of theabove-presented electrolyte formulations may be prepared without theaddition of lithium nitrate (LiNO₃) and/or other types ofnitrogen-oxygen containing additives.

FIGS. 23-25 show graphs depicting specific discharge capacity per cyclenumber for one or more of the Examples 1-20 presented earlier, accordingto some implementations. FIG. 23 shows a graph 2300 of specificdischarge capacity (mAh/g) per cycle number depicting performanceimprovements of the battery 100 of FIG. 1A and/or other batteryconfigurations disclosed herein. Regarding the graph 2300, “control”refers to the electrolyte 130 prepared according to Example 1, “Toluene”refers to the electrolyte 130 prepared according to Example 3, and “TMU”refers to the electrolyte 130 prepared according to Example 5. In someaspects, toluene in the electrolyte 130 prepared according to Example 3may provide favorable unexpected results based on its non-polar natureand correspondingly poor interactions with, for example, thepolysulfides 128 of FIG. 1B. That is, toluene has a unique chemicalstructure that may impede facile transport of the polysulfides 128through the electrolyte 130 when prepared according to Example 3.Benefits associated with usage of varying concentrations or dilutionlevels of toluene within, for example, the liquid solvent mixture (alsoreferred to as the ternary solvent package) may increase in significanceproportionate to cycling rate. That is, usage of toluene may be evenmore beneficial in terms of cathode capacity retention than that shownin the graph 2300 when observing a lithium-sulfur battery discharged ata C/3 rate (corresponding to complete battery discharge over a timeperiod of 3 hours) relative to a traditional discharge rate of 1C(corresponding to complete battery discharge over a time period of 1hour). In this way, toluene may be particularly well suited for end-useapplications that may involve longer battery life or discharge times,such as electric vehicles (EVs).

Toluene may be uniquely suited to out-perform other solvents based onits chemical structure and non-polar nature, having an approximate ionicconductivity value (mS/cm) of 5.128026. In this way, toluene in theelectrolyte 130, such as when prepared according to Example 3, maycontribute to higher specific capacity and improved capacity retentionduring battery cycling by impeding movement of the polysulfides 128within the electrolyte 130, thereby freeing up volume in the electrolyte130 available to transport the lithium cations (Li⁺) 125. In addition,or the alternative, toluene may act as a favorable solvent for theelemental sulfur 126, when pre-loaded (such as by capillary infusion orsome other suitable technique) into the cathode 110 or the cathode 2200.In one implementation, toluene may assist in the de-passivation of thecathode 110 or the cathode 2200 to pre-condition the battery 100 toprevent dropping beneath the minimum designed voltage (of the battery100) once the external load 172 is applied.

By impeding movement of the polysulfides 128 in the electrolyte 130,toluene may improve sulfur retention within the cathode 110 and overallsulfur related kinetics, that is sulfur utilization in formingcoordination complexes with the lithium cations (Li⁺) 125. Toluene alsomay improve interfacial regions between the anode 120 and theelectrolyte 130 by preventing movement of the polysulfides 128 fromcontacting the anode 120. In addition, toluene may increase the boilingpoint and/or decrease the volatility of the electrolyte 130, which mayimprove safety and reliability of the electrolyte 130. Further, toluenemay lower the freezing point of the electrolyte 130, which may assist inlow temperature performance of the battery 100. Toluene may also lowerthe density of the electrolyte 130 as well, which may improve specificenergy, since the mass of the electrolyte 130 may impact the performanceand/or efficiency of the battery 100.

In some implementations, the ability of toluene to improve theperformance of the electrolyte 130 may depend at least in part on theability of toluene to solubilize certain forms of elemental sulfur, suchas cyclooctasulfur (S₈). In some aspects, toluene may have a normalizedfirst cycle discharge capacity (Ah/g) of approximately between 0.6(Ah/g) to 0.8 (Ah/g) at a S₈ solubility level of approximately 0.0275(mol/L). These values present a marked improvement when compared to, forexample, ACN, which has a normalized first cycle discharge capacity(Ah/g) of approximately between 0.37 (Ah/g) to 0.41 (Ah/g) at a S₈solubility level of approximately 0.0075 (mol/L), indicating thattoluene tends to solvate S₈ better and provides correspondingly improvedischarge capacity.

FIG. 24 shows a graph 2400 of specific discharge capacity (mAh/g) percycle number depicting performance improvements of the battery 100 ofFIG. 1A and/or other battery configurations disclosed herein. Regardingthe graph 2400, “MPB” refers to the electrolyte 130 prepared accordingto Example 7, “TrigDME” refers to the electrolyte 130 prepared accordingto Example 9, and “TEE” refers to the electrolyte 130 prepared accordingto Example 8.

FIG. 25 shows a graph 2500 of specific discharge capacity (mAh/g) percycle number depicting performance improvements of the battery 100 ofFIG. 1A and/or other battery configurations. Regarding the graph 2500,“TFETFE” refers to the electrolyte 130 prepared according to Example 13,“DMTS” refers to the electrolyte 130 prepared according to Example 11,“MTBE” refers to the electrolyte 130 prepared according to Example 10,and “ACN” refers to the electrolyte 130 prepared according to Example12.

In some aspects, a cathode (such as the cathode 2200 of FIG. 22) may bepositioned opposite to an anode (such as the anode 120 of FIG. 1) andhave an overall porosity between 40% and 70%. In one example, thecathode 2200 may include non-hollow carbon spherical (NHCS) particlesjoined together. Each NHCS particle may be one example of the firsttri-zone particles 2212 of FIG. 22, the second tri-zone particles 2222of FIG. 22, the carbonaceous particle 800 of FIG. 8A, and/or the like.At least some NHCS particles may coalesce together and therebycollectively form tubular NHCS particle agglomerates, which may be oneexample of the aggregate 960 of FIG. 9B. Each NCHS particle may have adiameter between 30 nanometers (nm) and 60 nm, and may include a firstregion and a second region. In one implementation, the first region maybe defined by the first pores 801 of FIG. 8A, and the second region maybe defined by the second pores 802 of FIG. 8A. In this way, the firstregion may be adjacent to a center of a respective NHCS particle and mayhave a first density of carbonaceous materials, and the second regionmay be adjacent to a surface a respective NHCS particle. The secondregion may encapsulate the first region and have a second density ofcarbonaceous materials that is lower than the first density ofcarbonaceous materials. The first region and the second region may be influid communication with each other.

In addition, the cathode 2200 may include interconnected channels (notshown in FIG. 22 for simplicity) defined in shape by adjacent NHCSparticles. Some interconnected channels may be pre-loaded with anelemental sulfur and retain polysulfides (PS) based on one or more ofthe first density of carbonaceous materials or the second density ofcarbonaceous materials. An electrolyte, which may be prepared by any ofthe formulations presented in Examples 1-20, may be interspersedthroughout the cathode and in contact with the anode. A separator may bepositioned between the anode and the cathode.

FIG. 26A shows an example battery 2600A, according to some otherimplementations. The battery 2600A may be an example of other batteryconfigurations disclosed herein. In one implementation, the battery2600A may be implemented as a lithium-sulfur battery, and may include ananode 2620 (e.g., an anode active material comprising a foil oflithium), a cathode 2610, and a solid-state electrolyte 2630. In someinstances, the solid-state electrolyte 2630 may replace one or moreelectrolyte solution compositions presented in Examples 1-20. Thecathode 2610 may be one example of other cathode configurationsdisclosed herein, such as the cathode 110 of FIG. 1, the cathode 210 ofFIG. 2, and/or the cathode 2200 of FIG. 22. In some aspects, the cathodemay be loaded with elemental sulfur of 3 milligrams (mg) per cubiccentimeter (cm³). In other aspects, the cathode 2610 may be loaded withother concentrations of elemental sulfur of 3 milligrams (mg) per cubiccentimeter (cm³) suitable for maximizing the efficiency ofdischarge-charge cycling of the battery 2600A. In some aspects, thecathode 2610 may be porous and formed from a composition of matter (notshown in FIG. 26A for simplicity) including a plurality of pores 2612.The composition of matter may be one example of various carbonaceousmaterials and/or structures disclosed herein, such as the first tri-zoneparticles 2212 of FIG. 22, the second tri-zone particles 2222 of FIG.22, the carbonaceous particle 800 of FIG. 8A, one or more instances ofthe aggregate 960 of FIG. 9B and/or the like.

The solid-state electrolyte 2630 may be dispersed throughout at leastthe pores 2612 of the cathode 2610, and may also be in contact with theanode 2620. In some aspects, the solid-state electrolyte 2630 may beformed as a membrane and thereby provide ionic conduction capabilitiesassociated with a separator, such as the separator 150 of FIG. 1. In oneimplementation, the solid-state electrolyte 2630 may be formed fromand/or include a polymer matrix 2631, which may be formed of glassfibers 2633 interconnected with each other. In some aspects, the polymermatrix 2631 may have an ionic conductivity (e.g., conducting lithiumcations (Li⁺)) and may include between 8 weight percent (wt. %) and 12wt. % of polyethylene oxide (PEO) 2632, between 13 wt. % and 17 wt. % ofpolyvinylidene difluoride (PVDF) 2634, between 3 wt. % and 7 wt. % ofpolyetheramine 2535 having repeated oxypropylene units (not shown inFIG. 26A for simplicity) in its backbone, and between 5 wt. % and 10 wt.% of one or more lithium-containing salts including one or more oflithium bis(trifluoromethanesulfonyl)imide (LiTFSI) or lithium iodide(LiI) (not shown in FIG. 26A for simplicity). In some implementations,at least some of the lithium-containing salts may dissociate intolithium cations (Li⁺) and thereby assist in lithium ionic transportbetween the anode 2620 and the cathode 2610 during operationaldischarge-charge cycling of the battery 2600A.

Similar to the various other lithium-sulfur battery configurationsdisclosed herein, the battery 2600A may generate undesirablelithium-containing polysulfide species (not shown in FIG. 26A forsimplicity) during operational discharge-charge cycling of the battery2600A. In some instances, the cathode 2610 may at least partially trapand/or retain the lithium-containing polysulfide species, therebypreventing blockage of lithium transport pathways (e.g., as shown as acharge cycle flow 2625) within the solid-state electrolyte 2630. In someaspects, the anode 2620 may be formed as a layer of lithium thatprovides lithium cations (Li⁺) upon activation of the battery 2600A. Inthis way, the layer of lithium may provide lithium cations (Li⁺) duringoperational discharge-charge cycling of the battery 2600A. In otheraspects, the cavity 2622 may receive lithium deposits from the cathode2610 during operational charge cycling of the battery 2600A. That is,lithium cations (Li⁺) may travel along the charge cycling flow 2624 fromthe cathode 2610 to the cavity 2622 as may be associated with the returnof the electrons 2674 back towards the battery 2600A as may beencountered in or associated with battery charge and/or rechargecycling. In this way, the cavity 2622 may transform into the anode 2620,which may be capable of again providing lithium cations (Li⁺) to theirrespective electrochemically favored positions in the cathode 2610during operational discharge cycling of the battery 2600A.

In one implementation, the composition of matter used to form thecathode 2610 may be formed from and/or include one or more non-tri-zoneparticles, tri-zone particles, aggregates, or agglomerates as disclosedherein. In some aspects, the cathode 2610 may be one example of thecathode 2200 of FIG. 22. That is, each tri-zone particle used in thecathode 2610 may include carbon fragments intertwined with each other.At least some carbon fragments may be separated from one another bymesopores. A deformable perimeter may be defined upon coalescence of oneor more adjacent non-tri-zone particles or tri-zone particles. Eachaggregate may include a multitude of the tri-zone particles joinedtogether and have a principal dimension in a range between 10 nanometers(nm) and 10 micrometers (μm). Mesopores may be interspersed throughoutthe aggregates. Each mesopore may have a principal dimension between 3.3nanometers (nm) and 19.3 nm. Each agglomerate may be formed from amultitude of the aggregates joined to each other and have a principaldimension in an approximate range between 0.1 μm and 1,000 μm.Macropores may be interspersed throughout the aggregates, where eachmacropore having a principal dimension between 0.1 μm and 1,000 μm.

In some implementations, the ionic conductivity of the solid-stateelectrolyte 2630, when formed and/or deposited as a membrane (not shownin FIG. 26A for simplicity) on the anode 2620, may be based on relativeconcentration levels of one or more lithium-containing salts doped intothe polymer matrix 2631. In this way, the ionic conductivity of thesolid-state electrolyte 2630 may be between 0.97×10⁻³ siemens per meter(S/m) and 1.03×10⁻³ S/m at a temperature between 18 degrees Celsius (°C.) and 22° C. In other implementations, the membrane may be coated ontothe anode 2620, such that the ionic conductivity of the membrane isbetween 3.97×10⁻⁶ siemens per meter (S/m) and 4.03×10⁻⁶ S/m at atemperature between 18 degrees Celsius (° C.) and 22° C. In someaspects, higher quantities of one or more lithium-containing salts maybe associated with an increase in the ionic conductivity of the polymermatrix 2631.

In one implementation, the solid-state electrolyte 2630, when formed asa membrane, has a thickness between 10 micrometers (μm) and 50 μm, andmay have a uniform density throughout its thickness. For example, insome instances, the solid-state electrolyte 2630 may have a densitybetween 2 grams per cubic centimeter (g/cm³) and 3 g/cm³. In someaspects, the membrane may be coated onto a sacrificial polymer (notshown in FIG. 26A for simplicity), which may be disposed on the anode2620 facing the solid-state electrolyte 2630. In this way, thesolid-state electrolyte 2630 may prevent electrons from traveling fromthe anode 2620 to the cathode 2610 through the solid-state electrolyte2630. In addition, contact points between the solid-state electrolyte2630 and the anode 2620 may prevent impedance growth of the battery2600A.

In one implementation, the cathode 2610 has a thickness between 50micrometers (μm) and 150 μm, and a density between 5 grams per cubiccentimeter (g/cm³) and 15 g/cm³. In some aspects, the solid-stateelectrolyte 2360 may be prepared without a liquid-phase electrolyte,such as Examples 1-20 disclosed herein. In addition, or the alternative,the solid-state electrolyte 2630 may localize lithium-containingpolysulfide species within the cathode 2610 and/or prevent growth oflithium-containing dendritic structures from the anode 2620. In someaspects, the anode 2620 may volumetrically expand between 5% and 20% ofits initial size during operational discharge-charge cycling of thebattery 2600A. In some instances, the solid-state electrolyte 2630 mayprovide interfacial stability between the anode 2620 and the solid-stateelectrolyte 2630 during operational discharge-charge cycling of thebattery 2600A, for example, to reduce or limit volumetric expansion ofthe anode 2620.

FIG. 26B shows another example battery 2600B, according to some otherimplementations. In one implementation, the battery 2600B may be anotherexample of the battery 2600A. In some aspects, the cavity 2622 mayreplace the anode 2620, and may be incrementally filled with lithiumprovided from the cathode 2610 during operational discharge-chargecycling of the battery 2600B. In this way, once the cavity 2622 of FIG.26B is filled with lithium to become the anode 2620 of FIG. 26A, thebattery 2600B may function in a manner similar or identical to thebattery 2600A.

FIG. 27 shows a graph 2700 depicting voltage drop per specific capacityfor an example configuration of the battery 2600A of FIG. 26A, accordingto some implementations. Regarding the graph 2700, the battery 2600A wasprepared with a sulfur loading level of 3 milligrams (mg) per cubiccentimeter (cm³) and in a coil cell format. In addition, the battery2600A was prepared with the solid-state electrolyte 2630 at a thicknesslevel of 18 micrometers (μm). Region 2702 may be representative ofunique voltage drop behavior associated with formation and/ordissociation of lithium-containing polysulfide intermediates generatedduring discharge-charge operational cycling of the battery 2600A.

FIG. 28 shows another example battery 2800, according to some otherimplementations. The battery 2800 may be an example of other batteryconfigurations disclosed herein. In one implementation, the battery 2800may be implemented as a lithium-sulfur battery, and may include acathode 2810, an anode structure 2822 including an anode 2820 (e.g., ananode active material comprising a foil of lithium) positioned oppositeto the cathode, a separator 2850 positioned between the anode 2820 andthe cathode 2810, and an electrolyte 2830. In some aspects, theelectrolyte 2830 may be formulated by mixing at least two or moresolvents, such as those disclosed in Examples 1-20 presented earlier.The electrolyte 2830 may be dispersed throughout the cathode 2810 and incontact with the anode 2820. In some aspects, the anode 2820 may be asingle foil of solid metallic lithium. In this way, at least somelithium cations (Li⁺) 2825 output by the anode 2820 may participate indissociation reactions and/or combination reactions during operationaldischarge-charge cycling of the battery 2800. That is, lithium cations(Li⁺) 2825 output from the anode 2820 may be transported through theelectrolyte 2830 and retained in their electrochemically favoredpositions (not shown in FIG. 28 for simplicity) within the cathode 2810during discharge cycles of the battery 2800. Then, during charge cyclesof the battery 2800, the lithium cations (Li⁺) 2825 may be forced toreturn to the anode 2820 upon exposure to an outside current source.

In addition, a solid-electrolyte interphase 2840 may form on the anode2820. In this way, a protective layer 2860 may form at least partiallywithin and/or on the solid-electrolyte interphase 2840 and face thecathode 2810. In some aspects, the solid-electrolyte interphase 2840 mayform one or more compounds on the anode 2820 based on one or moreoxidation-reduction reactions involving lithium cations (Li⁺) and one ormore solvents of the electrolyte 2830. In some implementations, theprotective layer 2860 may be at least partially formed from carbonaceousmaterials including one or more of flat graphene, wrinkled graphene,carbon nano-tubes (CNTs), carbon nano-onions (CNOs), or non-hollowcarbon spherical particles (NHCS), one or more of which may be oneexample of the carbonaceous structure 956 of FIG. 9B.

FIG. 29 shows a diagram depicting an example cathode 2900, according tosome implementations. The cathode 2900 may be one example of othercathode configurations disclosed herein, such as the cathode 2200 ofFIG. 22 and/or the cathode 2810 of FIG. 28. In some implementations, thecathode 2900 may include a porous structure 2915 with interconnectedchannels 2916 defined by adjacent and interconnected non-hollow carbonspherical particles (NHCS) particles 2917, each of which may be oneexample of the tri-zone particle 850 of FIG. 8B, the aggregate 960 ofFIG. 9B, and/or other carbonaceous materials described in the presentdisclosure. In this way, at least some of the interconnected channels2916 may be loaded with elemental sulfur 2926 in the cathode 2900 priorto activation and discharge-charge cycling of, for example, the battery2800 of FIG. 28. The elemental sulfur 2926 may form coordinationcomplexes with at least some of the lithium cations (Li⁺) 2825 toincrease specific capacity of the cathode 2900, for example, compared toconventional lithium ion chemistries. In some aspects, the cathode 2900may have a width 2910 formed of a first region 2911 disposed on asubstrate 2902 (e.g., a copper or other metal current collector), andmay have multiple additional regions, such as a second region 2912positioned adjacent to the first region 2911. Each of the regionsincluding the first region 2911, the second region 2912, and/oradditional subsequent regions positioned adjacent to the second region2912 (not shown for simplicity in FIG. 29) may be defined in shape,size, and orientation by a respective concentration level of NHCSparticles 2917. That is, in some aspects, the first region 2911 may beprepared with a relatively higher concentration of NHCS particles 2917,thereby resulting in increased electrical conduction between adjacentgraphene sheets within each NHCS particle, as may be desirable near orat the substrate 2902. In contrast, the second region 2912 may beprepared with a relatively lower concentration of NHCS particles 2917,thereby permitting for additional transport of lithium ions (Li⁺) 2925into the width 2910 of the cathode 2900 for complexation with elementalsulfur 2926 contained within the interconnected channels 2916.

FIG. 30 shows a diagram 3000 depicting region “A” of the protectivelayer 2860 of the battery of FIG. 28, according to some implementations.In some aspects, region “A” may be one example of various anodeprotective layers disclosed herein, including the protective layer 2860.In one implementation, region “A” may be at least partially formed frompolymeric materials, such as a first polymeric chain 3010 with carbonatoms 3014 provided by at least some of the carbonaceous materials.Oxide anions (O²⁻) 3022, fluorine anions (F⁻) 3012, and nitrate anions(NO³⁻) 3024 may be uniformly dispersed throughout region “A” and graftedonto one or more of the carbon atoms 3014. Region “A” may also include asecond polymeric chain 3020 including at least some of the carbon atoms3014, which may be also provided by carbonaceous materials. Similar tothe first polymeric chain 3010, the carbon atoms 3014 of the secondpolymeric chain 3020 may also be grafted to one or more of oxide anions(O²⁻) 3022, fluorine anions (F⁻) 3012, and nitrate anions (NO³⁻) 3024,one or more of which may be uniformly dispersed throughout theprotective layer 2860. In some aspects, the second polymeric chain 3020may be positioned opposite to the first polymeric chain 3010. Inaddition, in one implementation, the first polymeric chain 3010 and thesecond polymeric chain 3020 may be configured to cross-link with eachother based on exposure to one or more nitrogen-containing groups, suchas the nitrate anions (NO³⁻) 3024.

In some aspects, inorganic and/or ionic conductor 3018, such aslithium-containing salts including lithiumbis(trifluoromethanesulfonyl)imide (LiTFSI), may be uniformly dispersedthroughout the electrolyte 2830 and/or the protective layer 2860, andthereafter dissociate into lithium cations (Li⁺) 2825 and TFSI⁻ anions2826. In addition, the first polymeric chain 3010 and the secondpolymeric chain 3020 may at least partially cross-link with each otherand form carbon-carbon bonds 3026 upon exposure to an environment 3050.In some instances, the environment 3050 may include a polymerizationinitiator and/or ultraviolet (UV) radiation.

Specifically, exposure of the first and second polymeric chains 3010 and3020 to the polymerization initiator and/or the UV radiation may causeregion “A” to be formed as a three-dimensional (3D) lattice having across-linking density defined by a number of cross-link points per-unitvolume. In some aspects, the cross-link points may be configured to atleast partially trap the TFSI⁻ anions 2826 produced upon dissociation ofLiTFSI. For example, the number of cross-link points per-unit volume mayrestrict re-dissolution of lithium-containing additives in region “A”toward the electrolyte 2830. In some aspects, the cross-linking densityof the protective layer 2860 may inhibit swelling above 10% of aninitial volume of the protective layer 2860 by, for example, preventingabsorption of at least one of the solvents in the electrolyte 2830. Insome other aspects, the cross-linking density of the protective layer2860 may control swelling between 10%-50% of an original volume of theprotective layer 2860 by controlling absorption of at least one solvent.In this way, the cross-linking density of the protective layer 2860 mayimprove and/or may be associated with an improvement of lithium ion(Li+) transport throughout the anode structure 2822 and the electrolyte2830.

In one implementation, the protective layer 2860 may have a modulus ofelasticity between 3 gigapascals (GPa) and 100 GPa, a glass transitiontemperature above 60° Celsius (C) and may cure at a temperature of lessthan 81° Celsius (C). Upon activation of the battery 2800, lithiumfluoride (LiF) may form based on one or more chemical reactions (e.g.,the Wurtz reaction of FIG. 7). For example, lithium fluoride (LiF) maybe configured to form based on a combination of fluorine anions (F−) andlithium cations (Li⁺). In some aspects, the combination of fluorineanions (F−) and lithium cations (Li⁺) may generate lithium oxide (Li₂O),lithium nitrate (LiNO₃) and/or nitrogen-oxygen containing compounds. Inone implementation, lithium fluoride (LiF) may be formed based on acombination of lithium cations (Li⁺) 2825 output from the anode 2820 andfluorine anions (F−) 3012 (of FIG. 30) grafted onto the first polymericchain 3010 and/or the second polymeric chain 3020. In some aspects, thecombination of lithium cations (Li⁺) 2825 and fluorine anions (F⁻) 3012may consume at least some of the lithium cations (Li⁺) 2825 output fromthe anode 2820, thereby reducing lithium-containing dendritic growth(not shown in FIG. 28 for simplicity) from the anode 2820. Reducinglithium-containing dendritic growth from the anode may, in turn,increase the charge rate, the discharge rate, the energy density, thecycle life of the battery 2800, or any combination thereof. In addition,lithium fluoride (LiF), lithium oxide (Li₂O), lithium nitrate (LiNO₃) ornitrogen-oxygen containing additives may form one or more regions acrossone or more of the anode 2820 or the solid-electrolyte interphase 2840.

In some aspects, the inorganic and/or ionic conductor 3018 of theprotective layer 2860 may include additives, such as lithium saltsincluding lithium nitrate (LiNO₃) and/or inorganic ionically conductiveceramics including one or more of lithium lanthanum zirconium oxide(LLZO), NASICON-type oxide Li_(1+x)Al_(x)Ti_(2-x)(PO₄)₃ (LATP) and/orlithium tin phosphorus sulfide (LSPS), and/or nitrogen-oxygen containingadditives. At least some of these additives dispersed throughout region“A” and/or the protective layer 2860 may dissociate to produce thelithium cations (Li⁺) 2825. In this way, the presence of at least someadditives within the protective layer 2860 may increase the charge rate,the discharge rate, and/or the energy density of the lithium-sulfurbattery 2800.

In one implementation, the first polymeric chain 3010 may be formed froma first plurality of interconnected monomer units, “C”, (e.g., of FIGS.36 and 37), and the second polymeric chain 3020 may be formed from asecond plurality of interconnected monomer units, “D”. In some aspects,the first plurality of interconnected monomer units, “C”, and the secondplurality of interconnected monomer units, “D”, may be identical. Inother aspects, the first plurality of interconnected monomer units, “C”,and the second plurality of interconnected monomer units, “D”, may bedistinct from each other.

In some aspects, the first polymeric chain 3010 and the second polymericchain 3020 may cross-link with each other based on exposure tonitrogen-containing groups (e.g., nitrate ions NO₃ ⁻), some of which maycure in an epoxy and/or include an amine-containing group. In addition,or the alternative, the first polymeric chain 3010 and/or the secondpolymeric chain 3020 may be prepared to include liquid bisphenol Aepichlorohydrin-based epoxy resin, polyoxyethylene bis(glycidyl ether)having an average M_(n) of 500 (PEG-DEG-500), andpolyoxypropylenediamine. For example, in one implementation, theprotective layer 2860 may be prepared to include between 2 wt. %-5 wt.%, of difunctional bisphenol A/epichlorohydrin derived liquid epoxyresin, between 15 wt. %-25 wt. % of polyoxyethylene bis(glycidyl ether)(PEG-DEG-500) having an average M_(n) of 500, between 20 wt. %-25 wt. %of diaminopolypropylene glycol, between 5 wt. %-15 wt. % ofpoly(propylene glycol) bis(2-aminopropyl ether), between 5 wt. %-15 wt.% of lithium bis(trifluoromethanesulfonyl)imide (LiTFSI), and between 40wt. %-60 wt. % of lithium lanthanum zirconium oxide (LLZO). In someother aspects, the protective layer 2860 may be prepared to includebetween 2 wt. %-5 wt. % of difunctional bisphenol A/epichlorohydrinderived liquid epoxy resin, between 15 wt. %-25 wt. % of polyoxyethylenebis(glycidyl ether) having an average M_(n) of 500, between 5 wt. %-15wt. % of 3,4-epoxy cyclohexyl methyl-3,4-epoxy cyclohexane carboxylate(ECC), between 15 wt. %-20 wt. % of lithiumbis(trifluoromethanesulfonyl)imide (LiTFSI), between 40 wt. %-60 wt. %of lithium lanthanum zirconium oxide (LLZO), and between 1 wt. %-5 wt. %of diphenyliodonium hexafluorophosphate (DPIHFP). In addition, theprotective layer 2860 may be coated and/or deposited onto the anode 2820by a roll-to-roll apparatus. For example, the protective layer is one ormore of spray coated, gravure coated, micro gravure coated, slot-diecoated, doctor-blade coated, and/or Mayer's rod spiral-coated onto theanode.

In some implementations, the battery 2800 may be arranged in one or moreadditional configurations. For example, the first polymeric chain 3010and the second polymeric chain 3020 may participate in one or morecross-linking polymerization reactions with each other and form theprotective layer 2860 based on exposure to one or more ultraviolet (UV)curing accelerators, including one or more cationic photo initiators. Asdiscussed, the UV curing accelerators may be provided by the environment3050, which may include an ultraviolet (UV) radiation source.

In some aspects, one or more cross-linking polymerization reactions mayinclude ring-opening polymerization (ROP). In addition, the one or moreultraviolet (UV) curing accelerators includes a plurality of oniumsalts, which may include one or more triphenylsulfonium salts, one ormore diazonium salts, one or more diaryliodonium salts, one or moreferrocenium salts, and/or one or more metallocene compounds. In someaspects, the one or more ultraviolet (UV) curing accelerators mayinclude one or more antimony salts and/or polyols, which may serve asreactive diluents.

In some aspects, the protective layer 2860 may be formed from multiplepolymers uniformly mixed together and/or cross-linked (e.g., viacationic polymerization and/or ultraviolet (UV curing)) to form athree-dimensional (3D) lattice. The protective layer 2860 may beformulated according to one or more recipes disclosed in formulationrecipe Examples 21-22 below:

Example 21: For Amine-Curable Epoxy-Based Membrane Compositions

Weight Percent Components (wt. %) of Total Polyoxyethylene bis(glycidylether) (PEG- 19.64 DEG-500) having an average M_(n) of 500 Undilutedclear difunctional bisphenol 3.62 A/epichlorohydrin derived liquid epoxyresin (e.g., EPON ™ Resin 828) Polyoxypropylenediamine (e.g., 10.04JEFFAMINE ® D-230) Lithium bis(trifluoromethanesulfonyl)imide 16.7(LiTFSI) Lithium Lanthanum Zirconium Oxide 50 (LLZO) - 500 nm particlesize

Example 22: For Amine-Curable Epoxy-Based Membrane Compositions

Weight Percent Components (wt. %) of Total Polyoxyethylene bis(glycidylether) (PEG- 11.7 DEG-500) having an average M_(n) of 5004,4′-Methylenebis(N,N-diglycidylaniline) 11.7 Polyoxypropylenediamine(e.g., 9.94 JEFFAMINE ® D-230) Lithiumbis(trifluoromethanesulfonyl)imide 16.7 (LiTFSI) Lithium LanthanumZirconium Oxide 50 (LLZO) - 500 nm particle size

In some aspects, the protective layer 2860 may be prepared following thesteps of Example 23, an example procedure for preparing a 30 milliliter(mL) sample-scale dispersion of any one or more of the formulationrecipes provided by Examples 21-22 and/or 24-28 disclosed herein:

Example 23: Procedure for Preparing the Protective Layer

Phase Steps 1. Dispersion Preparation 1. Weigh components listed in oneof the Examples 21-22 or 24- 28 outside of a glovebox; pour and/ordisperse the listed components into a 4 ounce (oz) glass bottle. 2.Transfer the bottle to inside a glovebox, weigh and optionally add LLZO(e.g., in the amount listed by the respective Example) and optionallyadd DME (e.g., depending on the level of dilution sought) as anon-reactive diluent. 3. Wrap bottle lid with paraffin, and sonicate thewrapped for a duration of 60 minutes (min.) outside the glovebox in afume hood, or inside glovebox if a sonicator is available; vortex thewrapped bottle for 1 min., then sonicate the wrapped for another 60 min.4. Transfer the bottle back to glovebox to prepare for spray coating theanode. 2. Spray coating 1. Clean a spray nozzle with acetone prior tospraying the liquid dispersion prepared in Phase 1. 2. Spray allcontents of the bottle (e.g., the entire dispersion) onto 6 centimeter(cm) by 60 cm lithium foil (e.g., the anode) within glovebox using thespray nozzle. 3. Spray for a total duration of approximately 30-45 min.3. (Optional) UV Curing 1. Expose the spray-coated dispersion (e.g.,protective layer 2860) disposed on the lithium anode foil to UV light(e.g., having a wavelength of 254 nanometers (nm)) for 10-20 seconds. 2.Repeat if desired to increase cross-linking density of the protectivelayer 2860. 4. Drying 1. Dry (e.g., cure) the spray-coated dispersion(e.g., protective layer 2860) onto the lithium anode foil at roomtemperature (18° C.-22° C.) for more than 24 consecutive hours withinthe glovebox.

When prepared according to Example 21, the protective layer 2860 has anon-set curing temperature of 68° C. and a glass-transition temperature(T_(g)) of −16° C. In some aspects, the protective layer 2860 may haveone or more openings, also referred to as “pinholes,” shown by a pinhole3102A in FIG. 31A formed in the protective layer 2860 that permit forundesirable pass-through of polysulfides 2882 towards the anode 2820 ina direction “B” of FIG. 28. The polysulfides 2882 may at least partiallycoat the anode 2820 and thereby impede free movement and/or transport ofthe lithium cations (Li⁺) 2825 between the anode 2820 and the cathode2810, which in turn may facilitate the discharge-charge cyclingoperation of the battery 2800. To address the undesirable formation ofpinholes in the protective layer 2860 when prepared according to Example21, the protective layer 2860 may be prepared according to Example 22.In this configuration, the protective layer 2860 has an on-set curingtemperature of 81° C., a curing peak temperature of 124° C., a curingenthalpy of 104 J/g, and a T_(g) of 63° C. Variations of either Example21 or Example 22 are possible where component loading levels areadjusted +/−3% from that listed. However, any formulation of theprotective layer 2860 may be prepared to result in T_(g) greater than60° C. and an on-set curing temperature of less than 81° C., or a curingpeak of less than 124° C., for the protective layer 2860 to cure at roomtemperature (e.g., 18° C.-22° C.). In addition, the protective layer2860 may be disposed onto the anode 2820 according to Example 23 with athickness between 100 nm to 3 μm.

The protective layer 2860 may be formulated according to either ofExample 21 or Example 22 by following the procedure set forth in Example23 to address commonly encountered operational challenges facingconventional lithium-sulfur batteries. For example, in conventionallithium-sulfur batteries using liquid-phase electrolyte solutions,unwanted and uncontrolled dissolution of polysulfides due to polysulfideshuttle may contribute to battery failure. In one or more particularexamples, polysulfide attack on lithium can cause rapid battery capacityreduction due to continuous solid-electrolyte interphase (SEI) growth.This growth consumes lithium cations, thereby resulting in fewer lithiumbeing available for transport through to the cathode for healthydischarge-charge operational cycling in conventional lithium-sulfurbatteries. In addition, remaining lithium cations may adhere to otherlithium cations due to, for example, gradients in electrochemicalpotential conducive for lithium-lithium metallic bonding, therebyproducing lithium-containing dendritic structures, which grow and extendfrom the anode towards the cathode and may thereby causeshort-circuiting of conventional lithium-sulfur batteries.

To protect lithium contained in the anode 2820 from the effects of polysulfide migration from the cathode 2810 to the anode 2820, and tosuppress lithium-containing dendrite formation, the protective layer2860 may be directly coated onto the anode 2820 prior to activation andoperational discharge-charge cycling of the battery 2800. As such, theprotective layer 2860 may be prepared to include the first polymericchain 3010 and the second polymeric chain 3020. Each of the first andsecond polymeric chains 3010 and 3020 may have repeating monomer units(e.g., of FIGS. 36 and 37), and may be identical or dissimilar to eachother. In addition, in some aspects, when the protective layer 2860 isformulated according to Example 21 or Example 22, at least some of thecarbon atoms 3014 on each polymeric chain may form carbon-carbon bondswith each other via ring-opening (ROP) cationic polymerization (e.g.,optionally catalyst-based), and may thereby form an amine-curableepoxy-based membrane. In some other aspects, when the protective layer2860 is formulated according one of Examples 24 to 28 (presented below),at least some of the carbon atoms 3014 on each polymeric chain may formcarbon-carbon bonds 3026 with each other via ultraviolet (UV) curableROP cationic polymerization.

In addition, catalyst-based or UV-curing of di- and/or multi-functionalcomponents may initiate and/or facilitate cross-linking of the firstpolymeric chain 3010 to the second polymeric chain 3020 by thecarbon-carbon bonds 3026 for efficient protection of the anode 2820.Functional groups (not shown in FIG. 28 or FIG. 30 for simplicity) maybe attached to at least some of the inorganic and/or ionic conductors3018 for additional tunability of the protective layer 2860. In thisway, the protective layer 2860, when formulated by any recipe disclosedby Example 21 through Example 28, may provide several advantagesrelative to conventional anode protective layers, which typically haveonly one component.

In some implementations, the protective layer 2860 may be formulated toinclude multiple polymeric components, such as where the first polymericchain 3010 and the second polymeric chain 3020 are different from eachother to make the protective layer 2860 relatively more flexible forcuring on and over the anode 2820 after spray-coating. This flexibilitymay prevent the protective layer 2860 from disintegrating during thefabrication process. In addition, directly coating the protective layer2860 onto the anode 2820 may uniformly strip and plate at least some ofthe lithium cations (Li+) 2825 during operational discharge-chargecycling of the battery 2800, thereby minimizing lithium dendriteformation. In some aspects, inorganic and/or ionic conductors 3018, suchas LLZO, dispersed throughout the protective layer 2860 may be ionicallyconductive and designed to minimize impedance growth of the battery2800. In addition, UV curing may be used to replace conventionalheat-drying processes to accelerate curing of the protective layer 2860and minimize potential adverse effects of processing time of theprotective layer 2860 on the anode 2820.

FIG. 31A shows a micrograph of an example baseline protective layer3100A, according to some implementations. The baseline protective layer3100A may be one example of the protective layer 2860 of FIG. 28 andprepared according to Example 21 presented earlier, thereby resulting information of the pinhole 3102A. In some aspects, the pinhole 3102A maybe sized as shown in FIG. 31A. In some other aspects, the pinhole 3102Amay be smaller or larger than as shown in FIG. 31A. In addition, thebaseline protective layer 3100A may have multiple instances of thepinhole 3102A, which collectively may negatively interfere with healthyoperational discharge-charge cycling of the battery 2800. For example,the pinhole 3102A may permit passage of at least some of thepolysulfides 2882 through the pinhole 3102 to contact the anode 2820and/or otherwise interfere with formation of the solid-electrolyteinterphase 2840, thereby reducing cycling efficiency of the battery2800.

FIG. 31B shows a micrograph of an example protective layer 3100B,according to some implementations. The protective layer 3100B may be oneexample of the protective layer 2860 of the battery of FIG. 28 whenprepared according to Example 22 by the process disclosed in Example 23.The protective layer 3100B may minimize pinhole formation to have nopinholes or one or more smaller pinholes 3102B, thereby reducing risk ofat least some of the polysulfides 2882 contacting the anode 2820 andcorrespondingly improving operational discharge-charge performance ofthe battery 2800.

FIG. 32 shows a micrograph of a cutaway 3200 of the protective layer2860 of the battery 2800 of FIG. 28, according to some implementations.The protective layer 2860 may be prepared according to Example 21 by theprocess disclosed in Example 23. In some other aspects, the protectivelayer 2860 may be prepared according to other recipes disclosed in theExamples, including Example 22.

FIG. 33A shows an example cross-linking density 3300A of the protectivelayer 2860 of the battery 2800 of FIG. 28, according to someimplementations. The cross-linking density 3300A may be one example of across-linking density of the protective layer 2860 when preparedaccording to Example 21 by the process disclosed in Example 23, andthereby have a certain number (e.g., 9) of cross-link points 3306A perunit area 3302A. In this way, each cross-link point 3306A may beseparated from adjacent cross-link points 3306A by a dimension 3304A.

FIG. 33B shows another example cross-linking density 3300B of theprotective layer 2860 of the battery 2800 of FIG. 28, according to someimplementations. The cross-linking density 3300B may be one example of across-linking density of the protective layer 2860 when preparedaccording to Example 22 by the process disclosed in Example 23, andthereby have a certain number (e.g., 25) of cross-link points 3306B perunit area 3302B. In this way, each cross-link point 3306B may beseparated from adjacent cross-link points 3306B by a dimension 3304B,which may be smaller than the dimension 3304A and thereby configured totrap at least some of the TFSI⁻ anions 2826 subsequent to dissociationof LiTFSI in the electrolyte 2830 and/or included in the protectivelayer 2860. By trapping at least some of the TFSI⁻ anions 2826 withinthe cross-linking density 3300B, the protective layer 2860 may functionto prevent the trapped TFSI⁻ anions 2826 from blocking passage of thelithium cations (L+) 2825 and/or contacting the anode 2820, therebyimproving operational discharge-charge cycling performance of thebattery 2800.

FIG. 34 shows an example ring-opening (ROP) mechanism 3400 fortriarylsulfonium salt (Ar₃S⁺MtXn⁻), according to some implementations.Generally, usage of UV initiators to initiate ROP polymerization viacross-linking of the first polymeric chain 3010 with the secondpolymeric chain 3020 may accelerate curing of the protective layer 2860from a maximum of 24 hours to 1-3 seconds, which may be desirable forlarge-scale manufacturing processes. In some aspects, usage of UVinitiators may accelerate epoxy cross-linking for existing epoxy systems(e.g., Examples 21-22, and/or Examples 24-28 to be disclosed herein),without requiring the additional introduction of new chemistries. Inaddition, UV initiators selected to enable epoxy cross-linking may becationic UV initiators. In this way, when various epoxies are exposed toUV radiation, they may produce a relatively strong Lewis acid and/orBrønsted-Lowry acid, which may then correspondingly initiate ROP ofepoxy groups.

The ROP mechanism 3400 is illustrated for triarylsulfonium salt(Ar₃S⁺MtXn⁻), which may be representative of the inorganic and/or ionicconductor 3018 incorporated in the protective layer 2860. In someaspects, HMtXn is a Lewis acid (e.g., HBF₄, HPF₆, HAsF₆, HSbF₆) and M isa monomer (e.g., of FIGS. 36 and 37 and/or including an epoxy group).Unlike free-radical polymerization, cationic polymerization (e.g.,including UV-initiated cationic ROP) is not inhibited by oxygen.However, polymer chain growth and cross-linking reactions may beinhibited by trace (e.g., less than 0.1 wt. %) of water and or chemicals(e.g., amines and/or urethanes). Nevertheless, initiating moieties inUV-initiated cationic ROP are relatively chemically stable for extendeddurations (e.g., more than 24 hrs.) In this way, polymerization inUV-initiated cationic ROP may continue even in the absence of visiblelight. In addition, some monomers (e.g., of FIGS. 36 and 37) and/oroligomers may be cured with lower UV dosages, depending on the amount ofthe protective layer 2860 sought for preparation.

FIG. 35 shows several example onium salts 3500 suitable for usage ascationic photo-initiators for the protective layer 2860 of the batteryof FIG. 28, according to some implementations. The onium salts 3500 maybe one example of the inorganic and/ionic conductor 3018 and may therebybe used to initiate cross-linking of the first polymeric chain 3010 withthe second polymeric chain 3020 to form the protective layer 2860. Insome aspects, the onium salts 3500 may include diphenyliodonium saltsand/or triphenylsulfonium salts (both shown in FIG. 35), as well asdiazonium salts, diaryliodonium salts, ferrocenium salts and/or variousother metallocene compounds (not shown in FIG. 35 for simplicity).Efficiency of the onium salts 3500 as cationic photo-initiators may atleast in part depend on their respective solubility in the protectivelayer 2860 (e.g., when formed as a resin), and/or their respectivepolarity and/or surface charge. Generally, solubility increases withincreasing size of anions in respective onium salts 3500 because chargeis dissipated over a relatively larger surface area of the anion, whichlowers hydrophilicity of the respective onium salt 3500. In this way,the solubility and reactivity of at least some of the onium salts 3500in non-ionic resins may increase along the order of tetrafluoroborate(BF⁴⁻)<hexafluorophosphate (PF⁶⁻)<hexafluoroarsenate (AsF⁶⁻)<fluoronium(SbF⁶⁻). In some aspects, antimony salts (e.g., including the fluoroniumanion) may be selected most often for use as cationic photo-initiators,due to their relatively higher solubility and reactivity, over the otherlisted salts. In addition, besides solubility alone, spectroscopicproperties such as range of light absorption and/or bond cleavageefficiency may affect the rate of initiation of polymerization ofmonomers in the first polymeric chain 3010 and/or the second polymericchain 3020.

FIG. 36 shows a several example monomers 3600 of various cationicphoto-polymerizable compositions suitable for forming the protectivelayer of the battery of FIG. 28, according to some implementations. Themonomers 3600 may each be one example of repeating monomer unit “C”and/or “D” of FIG. 30 and may thereby be used to initiate cross-linkingof the first polymeric chain 3010 with the second polymeric chain 3020to form the protective layer 2860. That is, multiple of instances ofrepeating monomer unit “C” may attach to exposed carbon and/or otheratoms to form the first polymeric chain 3010 of multiple units, e.g.,“C”-“C”-“C”- . . . etc., in the manner shown in FIGS. 30 and 36.Repeating monomer unit “D” may be identical or dissimilar to repeatingmonomer unit “C,” and thereby form the second polymeric chain in asimilar manner to the first polymeric chain by attaching to additionalinstances of repeating monomer unit “D,” e.g., “D”-“D”-“D”- . . . etc.,in the manner shown in FIGS. 30 and 36.

In some aspects, cationic UV resin formulations formed of at least someof the monomers 3600 may include examples of one or more cycloaliphaticepoxies, any one of which may be used as an epoxide group.Cycloaliphatic epoxies tend to be the relatively more reactive comparedto linear aliphatic groups or aromatic epoxy molecules, such that whenany one or more of the monomers 3600 are used to produce the protectivelayer 2860, a tight network of polar groups may form to yield arelatively brittle polymer-based final product. To reduce undesirablebrittleness, some UV cationic resin formulations may be prepared toinclude polyols (not shown in FIG. 36 for simplicity) as reactivediluents and performance modifiers. In some aspects, the polyols may actas monomeric materials, reacting into formed epoxy-based networks. Incomparison to cycloaliphatic epoxy groups alone, many different polyolsare available ranging from di and tri-functional glycols,polycaprolactone oligomers, and even high order dendritic polyols.Selecting between the relatively higher number of available polyols mayassist in fine-tuning of end-usage properties of the protective layer2860.

FIG. 37 shows ultraviolet (UV) curable monomers 3700 suitable forforming the protective layer 2860 of the battery 2800 of FIG. 28,according to some implementations. Monomers 3700 may be one example ofmonomer “B” and/or monomer “C” of FIG. 30 and may include diglycidyl1,2-cyclohexanedicarboxylate (DG-CHDC),3,4-epoxycyclohexylmethyl-3′,4′-epoxycyclohexane carboxylate (ECC),triphenylsulfonium triflate (TPS-TF), diphenyliodonium triflate(DPI-TF), diphenyliodonium hexafluorophosphate (DPI-HFP), poly[(phenylglycidyl ether)-co-formaldehyde] (PPGEF), and/or glycidyl2,2,3,3-tetrafluoropropyl ether (GTFEP).

In some aspects, the protective layer 2860 may be formed from multiplepolymers (e.g., formed from the monomers 3700) uniformly mixed togetherand/or cross-linked (e.g., via ultraviolet (UV curing) with a UV-curingwavelength of 254 nanometers (nm)) to form a three-dimensional (3D)lattice disposed on the anode 2820. The protective layer (e.g., whenformed as the 3D lattice) may be formulated according to one or morerecipes disclosed in Examples 24-28 below:

Example 24: UV-Curable Recipe

Function Components Wt. % Soft Oligomeric Epoxy (e.g., used as aPolyoxyethylene bis(glycidyl ether) 16.64 flexible spacer to decreasebrittleness (PEG-DEG-500) having an average M_(n) of the protectivelayer 2860) of 500 Rigid Polymeric Epoxy (e.g., used as a Undilutedclear difunctional bisphenol 3.62 flexible spacer to decreasebrittleness A/epichlorohydrin derived liquid epoxy of the protectivelayer 2860) resin (e.g., EPON ™ Resin 828) Fast Curing Epoxy MonomerDiglycidyl 1,2-cyclohexanedicarboxylate 8.04 (DG-CHDC) Photo-initiatorTriphenylsulfonium triflate (TPS-TF) 5.00 Inorganic and/or IonicConductor Lithium 16.7 bis(trifluoromethanesulfonyl)imide (LiTFSI)Inorganic and/or Ionic Conductor (e.g., Lithium lanthanum zirconiumoxide 50.0 used as a UV-screen to minimize acid (LLZO) (500 nm particlesize) formation on exposed surfaces of the protective layer 2860)

Example 25: UV-Curable Recipe

Function Components Wt. % Soft Oligomeric Epoxy (e.g., used as aPolyoxyethylene bis(glycidyl ether) 19.64 flexible spacer to decreasebrittleness of (PEG-DEG-500) having an average M_(n) the protectivelayer 2860) of 500 Rigid Polymeric Epoxy (e.g., used as a Undilutedclear difunctional bisphenol 3.62 flexible spacer to decreasebrittleness of A/epichlorohydrin derived liquid epoxy the protectivelayer 2860) resin (e.g., EPON ™ Resin 828) Fast Curing Epoxy Monomer3,4-epoxycyclohexylmethyl-3′,4′- 8.04 epoxycyclohexane carboxylate (ECC)Photo-initiator Diphenyliodonium 2.00 hexafluorophosphate (DPI-HFP)Inorganic and/or Ionic Conductor Lithium 16.7bis(trifluoromethanesulfonyl)imide (LiTFSI) Inorganic and/or IonicConductor Lithium lanthanum zirconium oxide 50.0 (LLZO) (500 nm particlesize)

Example 26: UV-Curable Recipe

Function Components Wt. % Soft Oligomeric Epoxy Polyoxyethylenebis(glycidyl ether) (PEG- 17.8 DEG-500) having an average M_(n) of 500Rigid Polymeric Epoxy PPGEF (Number Average Molecular 3.5 Weight (Mn) =345) Fast Curing Epoxy Monomer Diglycidyl 1,2-cyclohexanedicarboxylate7.0 (DG-CHDC) Photo-initiator Diphenyliodonium triflate (DPI-TF) 5.0Inorganic and/or Ionic Conductor Lithiumbis(trifluoromethanesulfonyl)imide 16.7 (LiTFSI) Inorganic and/or IonicConductor Lithium lanthanum zirconium oxide 50.0 (LLZO) (500 nm particlesize)

Example 27: UV-Curable Recipe

Function Components Wt. % Soft Oligomeric Epoxy Polyoxyethylenebis(glycidyl ether) (PEG- 19.8 DEG-500) having an average M_(n) of 500Rigid Polymeric Epoxy PPGEF (Number Average Molecular Weight 4.5 (Mn) =570) Fast Curing Epoxy Monomer 3,4-epoxycyclohexylmethyl-3′,4′- 7.0epoxycyclohexane carboxylate (ECC) Photo-initiator Diphenyliodoniumhexafluorophosphate (DPI- 2.0 HFP) Inorganic and/or Ionic ConductorLithium bis(trifluoromethanesulfonyl)imide 16.7 (LiTFSI) Inorganicand/or Ionic Conductor Lithium lanthanum zirconium oxide (LLZO) 50.0(500 nm particle size)

In some aspects, polyethylene glycol (PEG), other polyethers and/orother polyols may be used and/or substitutes for any of the componentslisted in Examples 23-27 depending on the performance requirements forthe protective layer 2860. In addition, variations of Examples 24-27 arepossible where component loading levels are adjusted +/−3% from thatlisted. In addition, all listed components, except forpolyoxypropylenediamine (e.g., JEFFAMINE® D-230), are compatible withUV-catalyzed cationic ROP. In this way, the first polymeric chain 3010may initiate cross-linking with the second polymeric chain 3020 to formthe carbon-carbon bonds 3026 and produce a 3D lattice disposed on theanode 2820. The 3D lattice may be formed of the various componentslisted in each Example, where the components are uniformly mixedtogether, interconnected with each other, and dispersed throughout theprotective layer 2860. That is, the first polymeric chain 3010 and thesecond polymeric chain 3020 are exemplary and additional polymericchains are possible, depending on the Example. Some Examples may includeadditional polymeric chains cross-linked to each other as well as one ormore of the first polymeric chain 3010 or the second polymeric chain3020. In addition, each component listed in any one or more of theExamples 21-22 and/or 24-28 may be formed of a corresponding polymericchain.

That is, in Example 26, which is representative of the other Examples,polyoxyethylene bis(glycidyl ether) (PEG-DEG-500) having an averageM_(n) of 500 may be denoted as monomer “B” in the first polymeric chain3010 and diglycidyl 1,2-cyclohexanedicarboxylate (DG-CHDC) may bedenoted as monomer “C” in the second polymeric chain 3010. Monomer “B”may bond with additional instances of monomer “B” and also bond with oneor more instance of monomer “C” in 3D to form the 3D lattice. Additionalcomponents (not shown in FIG. 30 for simplicity), may be denoted asmonomer “D” and so forth. For example, in Example 26, PPGEF (NumberAverage Molecular Weight (Mn)=345) may be denoted as monomer “D” andbond to additional instances of itself as well as monomer “B” and/ormonomer “C” in 3D to form the 3D lattice, where lithiumbis(trifluoromethanesulfonyl)imide (LiTFSI) and/or lithium lanthanumzirconium oxide (LLZO) (500 nm particle size) may be depicted as theinorganic and/or ionic conductor 3018 and dispersed throughout theprotective layer 2860.

Certain fast-curing cycloaliphatic epoxy monomers (e.g.,3,4-epoxycyclohexylmethyl-3′,4′-epoxycyclohexane carboxylate (ECC)),such as included in Examples 25 and 27 above, may be incorporated intothe protective layer 2860, to rapidly cross-link together at highercross-linking density levels such as the cross-linking density 3300B ofFIG. 33B via cationic polymerization processes to produce a network ofpolar groups to at least partially trap the TFSI⁻ anions 2826 within theprotective layer 2860. In addition, in some aspects, various UVinitiators (e.g., onium sales of hexafluorophosphate (PF₆ ⁻), which maybe beneficial for formation of the solid-electrolyte interphase 2840)may be substituted for the photo-initiators disclosed in Examples 24-27.In some other aspects, the anion for fluoroantimonic acid (SbF₆ ⁻) maybe substituted for the photo-initiators disclosed in Examples 24-27. Theanion for fluoroantimonic acid (SbF₆ ⁻) is soluble in the electrolyte2830 and may facilitate alloying of at least some regions of theprotective layer 2860 with at least some of the lithium cations (Li⁺)2825. In this way, alloying of some regions of the protective layer 2860may consume at least some of the lithium cations (Li⁺) 2825, therebyremoving the consumed lithium cations from participating inlithium-lithium metallic bonding to form undesirable dendrites from theanode 2820 towards the cathode 2810.

In addition, in one implementation, lithiumbis(trifluoromethanesulfonyl)imide (LiTFSI) may act as a co-initiatoronce UV curing has been initiated (e.g., by any of the photo-initiatorslisted in Examples 24-27), thereby increasing curing rates. For example,activation of the ROP reaction of an example monomer, poly(ethyleneglycol) diglycidyl ether (DGEPEG) may be achieved using lithiumbis(trifluoromethanesulfonyl)imide (LiTFSI) with a subsequentpropagation step. In the activation step, the lithium cation (e.g.,provided by LiTFSI) attacks the carbon-oxygen bond on one or moreepoxides of DGEPEG. As this reaction occurs under acidic conditions, theepoxide is converted to a hydroxyl ion. During the initiation andpropagation steps, the hydroxyl ions react with epoxides and otherhydroxyl ions via a nucleophilic reaction yielding chain extension viathe formation of C—O—C bonds.

In alternative to Examples 24-27 presented earlier, the protective layer2860 may be formulated to include fluorinated materials (e.g.,fluoropolymers, such as glycidyl 2,2,3,3 tetrafluoropropyl ether(GTFEP)) to be at least partially grafted onto the carbon atoms 3014. Inthis way, GTFEP may be used as a source of the fluorine ions (F⁻) 3012,which may later dissociate from their respective carbon atoms to combinewith the lithium cations (Li⁺) 2825 to produce lithium fluoride (LiF)via the Wurtz reaction, as discussed elsewhere in the presentdisclosure. Example 28 may be prepared according to the procedureprovided by Example 23 to include the following components:

Example 28: Fluorinated Polymer

Weight Percent Components (wt. %) of Total Polyoxyethylene bis(glycidylether) (PEG- 14.7 DEG-500) having an average M_(n) of 500 Glycidyl2,2,3,3- 10.5 tetrafluoropropyl ether (GTFEP) Undiluted cleardifunctional bisphenol 2.7 A/epichlorohydrin derived liquid epoxy resin(e.g., EPON ™ Resin 828) Polyoxypropylenediamine (e.g., JEFFAMINE ® 7.5D-230) Lithium bis(trifluoromethanesulfonyl)imide 14.3 (LiTFSI) One ormore surfactants (e.g., cationic 1.0 surfactants such as alkyl trimethylammonium, R—N(CH₃)₃ ⁺, dissolved in seawater (SW)) Lithium lanthanumzirconium oxide (LLZO) 49.3 (500 nm particle size)

Example 28 as presented above may not be initiated by UV curing, aspolyoxypropylenediamine (e.g., JEFFAMINE® D-230) may not be compatiblewith UV-catalyzed cationic ROP. However, in some aspects,polyoxypropylenediamine (e.g., JEFFAMINE® D-230) may be replaced by3,4-epoxycyclohexylmethyl-3′,4′-epoxycyclohexane carboxylate (ECC) tothereby render Example 28 UV-curable, similar to Examples 23-27.

FIG. 38 shows several example non-reactive diluents 3800 suitable forusage as additives to adjust dilution levels in UV-curable formulationsprepared with the UV curable monomers of FIG. 37, according to someimplementations. In one implementation, the non-reactive diluents mayinclude 1,2-Dimethoxyethane (DME) and/or triethylene glycol dimethylether (TEGDME). In some aspects, the non-reactive diluents 3800 may beremoved from the protective layer 2860 after cross-linking by baking at100° C. In some other aspects, the non-reactive diluents 3800 may beretained in the protective layer 2860 to enhance diffusion of thelithium cations (Li⁺) 2825.

FIG. 39 shows several example reactive diluents 3900 suitable for usageas additives to adjust dilution levels in UV-curable formulationsprepared with the UV curable monomers of FIG. 37, according to someimplementations. In some aspects, reactive diluents may function asflexibilizers to release stress of at least some of the carbon atoms3014 (e.g., which may be cross-linked to each other) within theprotective layer 2860 to thereby minimize pinhole formation. Inaddition, in some aspects, the non-reactive diluents 3800 and/or thereactive diluents 3900 may be or include materials used as additives forUV-curable formulations in the amount between 1 wt. % and 50 wt. % performulation weight to adjust the viscosity depending on depositionmethod (e.g., low viscosity for spray coating compared to high viscosityfor slot die or draw-down coating methods). In this way, the remainingcomponents are diminished in proportion to the amount of diluent added.

FIG. 40A shows a graph 4000A of capacity (% of initial) against cyclenumber, according to some implementations. The graph 4000A depictsperformance of the battery 2800 when prepared according to Example 22against Example 21 and an unprotected 40 μm lithium anode (e.g.,provided as a reference, “Ref.”). Example 22 shows consistently highercapacity retention (e.g., in % of original) per operationaldischarge-charge cycle number than both Example 21 and the unprotected40 μm lithium anode.

FIG. 40B shows a graph of capacity (mAh/g) against cycle number,according to some implementations. The graph 4000A depicts performanceof the battery 2800 when prepared according to Example 22 againstExample 21 and an unprotected 40 μm lithium anode (e.g., provided as areference, “Ref.”). Example 22 shows consistently higher capacityretention (e.g., in milli-amp hours per gram, mAh/g) per operationaldischarge-charge cycle number than both Example 21 and the unprotected40 μm lithium anode. The graph 4000A depicts performance of the battery2800 when prepared according to Example 22 against Example 21 and anunprotected 40 μm lithium anode (e.g., provided as a reference, “Ref.”).Example 22 shows consistently higher capacity retention (e.g., in % oforiginal) per operational discharge-charge cycle number than bothExample 21 and the unprotected 40 μm lithium anode.

FIG. 41A shows another graph of capacity (% of initial) against cyclenumber, according to some implementations. The graph 4100A depictsperformance of the battery 2800 when prepared according to Example 28against Example 21 and an unprotected 40 μm lithium anode (e.g.,provided as a reference, “Ref.”). Example 22 shows consistently highercapacity retention (e.g., in % of original) per operationaldischarge-charge cycle number than both Example 21 and the unprotected40 μm lithium anode.

FIG. 41B shows another graph of capacity (mAh/g) against cycle number,according to some implementations. The graph 4100B depicts performanceof the battery 2800 when prepared according to Example 28 againstExample 21 and an unprotected 40 μm lithium anode (e.g., provided as areference, “Ref.”). Example 22 shows consistently higher capacityretention (e.g., mAh/g) per operational discharge-charge cycle numberthan both Example 21 and the unprotected 40 μm lithium anode.

FIG. 42A shows another example battery 4200A, according to some otherimplementations. The battery 4200A may be an example of other batteryconfigurations disclosed herein. In one implementation, the battery4200A may be implemented as a lithium-sulfur battery, and may include acathode 4210, an anode structure 4222 including an anode 4220 positionedopposite to the cathode, a separator 4250 positioned between the anode4220 and the cathode 4210, and an electrolyte 4230. The anode 4220 maybe disposed on and/or coupled with a substrate 4201, such as a metalcurrent collector formed from nickel (Ni) or Aluminum (Al), etc. Thecathode 4210 may be disposed on and/or coupled with a substrate 4202,such as a metal current collector formed from nickel (Ni) or Aluminum(Al), etc. In some aspects, the electrolyte 4230 may be formulated bymixing at least two or more solvents, such as those disclosed inExamples 1-20 presented earlier. The electrolyte 4230 may be dispersedthroughout the cathode 4210 and in contact with the anode 4220. In someaspects, the anode 4220 may be a single foil of solid metallic lithium.In this way, at least some lithium cations (Li⁺) 2825 output by theanode 4220 may participate in dissociation reactions and/or combinationreactions during operational discharge-charge cycling of the battery4200A. That is, lithium cations (Li⁺) 4225 output from the anode 4220may be transported through the electrolyte 4230 and retained in theirelectrochemically favored positions (not shown in FIG. 42A forsimplicity) within the cathode 4210 during discharge cycles of thebattery 4200A. Then, during charge cycles of the battery 4200A, thelithium cations (Li⁺) 4225 may be forced to return to the anode 4220upon exposure to an outside current source.

In addition, a solid-electrolyte interphase (SEI) layer 4240 may beformed on the anode 4220. In some aspects, a protective layer 4260 maybe formed at least partially within and/or on the SEI layer 4240 andface the cathode 4210. In some aspects, the SEI layer 4240 may be formedfrom one or more compounds on the anode 4220 responsive to on one ormore oxidation-reduction reactions involving lithium cations (Li⁺) andone or more solvents of the electrolyte 4230. In some implementations,the protective layer 4260 may be at least partially formed fromcarbonaceous materials including one or more of flat graphene, wrinkledgraphene, carbon nano-tubes (CNTs), carbon nano-onions (CNOs), ornon-hollow carbon spherical particles (NHCS), one or more of which maybe one example of the carbonaceous structure 956 of FIG. 9B.

In one implementation, the anode 4220 of the anode structure 4222 may beformed as a single layer of solid lithium, which may output lithiumcations (Li⁺) during operational discharge cycling of the lithium-sulfurbattery. The SEI layer 4240 may be formed on the single layer of solidlithium, and the protective layer 4260 may be formed on and at leastpartially disposed within the SEI layer 4240 responsive to operationaldischarge-charge cycling of the lithium-sulfur battery 4200A. Theprotective layer 4260 may be an example of other protective layerconfigurations disclosed herein, including the protective layer 2860 ofFIG. 28.

In addition, or the alternative, the protective layer 4260 may include apolymeric backbone chain 4262 formed of interconnected carbon atoms4263. In this way, at least some of the interconnected carbon atoms 4263may move during operational discharge-charge cycling of the battery4200A and define a cooperative segmental mobility (also referred to as“segmental motion”) of the protective layer 4260. Additional polymericchains 4264 may be cross-linked to one another and to at least some ofthe interconnected carbon atoms 4263 of the polymeric backbone chain4262. Each of the additional polymeric chains 4264 may be formed ofinterconnected monomer units 4266. In some aspects, a plasticizer 4268may be dispersed throughout the protective layer 4260 without covalentlybonding to at least some of the interconnected carbon atoms 4263 of thepolymeric backbone chain 4262. In some aspects, the plasticizer 4268 maybe formed of and/or may include one or more of a polyethylene glycol(PEG or PEO) based oligomer, a nitrile, such as succinonitrile,glutaronitrile, adiponitrile. In addition, or the alternative, theplasticizer 4268 may be formed from and/or may include a solvent,including dimethoxyethane (DME), tetrahydrofuran (THF), diethyl ether,dioxolane (DOL), tetraethylene glycol dimethyl ether (TEGDME), toluene,bis(2,2-trifluoroethyl ether) (TEE), fluoroethylene carbonate (FEC),diethyl carbonate (DEC), dimethyl carbonate (DMC), propylene carbonate(PC), and/or ethylene carbonate (EC). The plasticizer 4268 may separateadjacent monomer units (e.g., by a spacing 4267 of FIG. 42B) of theinterconnected monomer units 4266 of at least some of the additionalpolymeric chains 4264. Increasing the separation between adjacentmonomer units may increase the cooperative segmental mobility of atleast some of the additional polymeric chains 4264, thereby increasingan ionic conductivity of the protective layer 4260. In addition, in someaspects, increasing the concentration levels of the plasticizer 4268 inthe protective layer 4260 may increase lithium cation (Li⁺) conductivitythrough the protective layer 4260. In some other aspects, linearpolymeric and/or oligomeric chains (not shown in FIG. 42A forsimplicity) may be covalently bonded, grafted, and/or cross-linked bycross-linking 4265) to at least some of the interconnected carbon atoms4263 of the polymeric backbone chain 4262. In this way, the linearpolymeric and/or oligomeric chains may increase the cooperativesegmental mobility (e.g., the maximum cooperative segmental mobility) ofthe protective layer 4260, which may increase lithium cation (Li⁺)conductivity through the protective layer 4260. For example, oligomericsubstances such as polyoxypropylenediamine (e.g., JEFFAMINE® M-600) mayincrease the cooperative segmental mobility (e.g., the maximumcooperative segmental mobility) of the protective layer 4260.

In some instances, the protective layer 4260 may be configured to meltat a glass transition temperature (T_(g)), such that increasing theglass transition temperature causes a reduction in the cooperativesegmental mobility (e.g., the maximum cooperative segmental mobility) ofthe polymeric chains. In addition, reducing the cooperative segmentalmobility (e.g., the maximum cooperative segmental mobility) of polymericchains may decrease lithium cation (Li⁺) conductivity through theprotective layer 4260. In this way, aspects of the present disclosuremay maximize lithium cation (Li⁺) conductivity through the protectivelayer 4260 by configuring the glass transition temperature to be lessthan room temperature (e.g., 18° C.-22° C.).

In some aspects, the protective layer 4260 may be prepared by Example 23according to the formulation recipe provided by Example 29 disclosedbelow:

Example 29: Plasticizer-Inclusive Recipe

Function Components Wt. % Wt. % Range Monomer “C” of Poly(ethyleneglycol) diglycidyl 17.5 10.0-50.0  FIG. 30 ether (PEGDGE) Monomer “D” ofUndiluted clear difunctional 3.2 1.0-30.0 FIG. 30 bisphenolA/epichlorohydrin derived liquid epoxy resin (e.g., EPON ™ Resin 828)Cross-Linker Polyoxypropylenediamine (e.g., 9 5.0-25.0 JEFFAMINE ®D-230) Plasticizer Tetraethylene glycol dimethyl ether 3.6 1.0-40.0(TEGDME or tetraglyme) Inorganic and/or Ionic Lithium 16.7 5.0-50.0Conductor (e.g., salt) bis(trifluoromethanesulfonyl)imide (LiTFSI)Inorganic and/or Ionic Lithium lanthanum zirconium oxide 50.0 25.0-90.0 Conductor (LLZO) (500 nm particle size)

In some other implementations, the protective layer 4260 may be formedon the anode as a three-dimensional (3D) polymeric lattice (not shown inFIG. 42A for simplicity) that includes a first polymeric chain and asecond polymeric chain positioned opposite one another. In some aspects,the first and second polymeric chains may be examples of the first andsecond polymeric chain 3010 and 3020, respectively of region “A” shownin the diagram 3000 of FIG. 30. In some implementations, each of thefirst and second polymeric chains may include carbon atoms at leasttemporarily chemically bonded to oxide ions (O²⁻), fluorine anions (F⁻),and/or nitrate anions (NO₃ ⁻). Lithiumbis(trifluoromethanesulfonyl)imide (LiTFSI) (not shown in FIG. 42A forsimplicity) may be dispersed throughout the 3D polymeric lattice todissociate into lithium cations (Li⁺) 4225 and TFSI− anions 4226. Inthis way, the first and second polymeric chains may form the 3Dpolymeric lattice with a cross-linking density sufficient to trap theTFSI− anions 4226 by cross-linking 4265 with each other. For example,the cross-linking 4265 may be initiated upon exposure to an energeticenvironment including ultraviolet (UV) energy and LiTFSI, where LiTFSImay serve as a polymerization co-initiator compound.

In other implementations, the first and second polymeric chains may formthe 3D polymeric lattice through cross-linking polymerization reactions,which may include a ultraviolet (UV) curing that may progress at acuring rate. In some aspects, the polymerization co-initiator compoundmay increase the curing rate. In some instances, additives are disperseduniformly throughout the 3D polymeric lattice, and may include lithiumnitrate (LiNO₃), inorganic ionically-conductive ceramics includinglithium lanthanum zirconium oxide (LLZO), NASICON-type oxideLi_(1+x)Al_(x)Ti_(2-x)(PO₄)₃ (LATP) or lithium tin phosphorus sulfide(LSPS), or nitrogen-oxygen containing additives. In this way, inorganicionically-conductive ceramics may be uniformly embedded in the 3Dpolymeric lattice and/or uniformly distributed in the protective layer4260. In some aspects, the protective layer 4260 may include desiccatedsolvents.

In some additional or alternative implementations, the protective layer4260 may trap various types of anions (not shown in FIG. 42A forsimplicity). For example, the protective layer 4260 may be formed ofmultiple ingredients including relatively pliable oligomeric epoxyand/or polyol based compounds, a relatively rigid polymeric epoxy basedcompound, and/or photo-initiator molecules. In some aspects, at leastsome of the relatively pliable oligomeric epoxy and/or polyol basedcompounds may prevent formation of pinholes in the protective layer4260. Lithium-containing salts dispersed uniformly throughout theprotective layer 4260 may dissociate into lithium (Li+) cations andvarious types of anions.

In addition, in some instances, the protective layer 4260 may be formedon the anode responsive to exposure to an ultraviolet (UV) energeticsource that facilitates a UV curing of at least some of the ingredientsof the protective layer 4260. In addition, in some aspects, theprotective layer 4260 may include non-reactive diluents including1,2-Dimethoxyethane (DME), tetrahydrofuran (THF), triethylene glycoldimethyl ether (TEGDME), or 2-Methyl-2-oxazoline (MOZ). In some otheraspects, the protective layer 4260 may include reactive diluentsincluding 1,3-Dioxolane (DOL), 3,3-Dimethyloxetane (DMO),2-Ethyl-2-oxazoline (EOZ), or ε-Caprolactone (CL). In this way, aper-unit formulation weight of the protective layer 4260 may be based ona concentration level of non-reactive diluents or reactive diluentsrelative to ingredients of the protective layer 4260. In some aspects,the reactive diluents may reduce mechanical stress of at least somecross-linking units within the protective layer 4260.

In some aspects, reactive diluents may be removed from the protectivelayer 4260. In some other aspects, reactive diluents may remain in theprotective layer 4260 after cross-linking 4265 of at least some of themultiple ingredients (e.g., relatively pliable oligomeric epoxy and/orpolyol based compounds, the relatively rigid polymeric epoxy basedcompound, and/or photo-initiator molecules) with one another. Theretention of reactive diluents in the protective layer 4260 aftercross-linking of two or more ingredients may increase lithium cation(Li⁺) 4225 diffusion through the electrolyte 4230. In oneimplementation, the relatively rigid polymeric epoxy based compound maybe formed from several repeating epoxy monomer units. For example, eachrepeating epoxy monomer unit is 3,4-epoxycyclohexylmethyl3,4-epoxycyclohexanecarboxylate (ECC), which may cross-link withadditional ECC monomer units and produce a network of polar groups (notshown in FIG. 42A for simplicity). The network of polar groups may trapat least some anions produced upon dissociation of lithium-containingsalts.

FIG. 42B shows a diagram 4200B of an enlarged section “E” of the battery4200A of FIG. 42A, according to some implementations. In some aspects,the plasticizer 4268 may cross-link (e.g., by the cross-linking 3265)with additional monomer units and is not chemically (e.g., covalently)bonded with the interconnected carbon atoms 4263 of the polymericbackbone chain 4262. At least some of the cross-linking 4265 of theplasticizer 4268 may volumetrically expand and/or contract to impartflexibility to the protective layer 4260. In this way, the protectivelayer 4260 may expand and/or contract as needed to accommodatevolumetric expansion of the anode 4220 resulting from operationaldischarge-charge cycling of the battery 4200A.

In one implementation, the plasticizer 4268 may affect the cooperativesegmental mobility (e.g., the maximum cooperative segmental mobility) ofthe protective layer 4260. For example, in the absence of theplasticizer 4268, the 3D lattice of the protective layer 4260 may berelatively rigid due to higher degrees of cross-linking 4265, which inturn may minimize the spacing 4267 between adjacent monomer units of theinterconnected monomer units 4266. Introduction of the plasticizer 4268between adjacent monomer units may increase the spacing 4267, whichprovides the additional polymeric chains more volume in which to move,thereby resulting in additional segmental motion of the protective layer4260. For example, since the plasticizer 4268 is not covalently bondedto the interconnected carbon atoms 4263 of the polymeric backbone chain4262, the plasticizer may be able to retain a relatively higher freedomof mobility within the 3D lattice of the protective layer. Thisrelatively higher freedom of mobility of the plasticizer 4268 may expandthe spacing 4267 between adjacent monomer units, thereby increasing theflexibility of the protective layer 4260 as may be necessary toaccommodate volumetric expansion of the anode 4220 associated withoperational discharge-charge cycling of the battery 4200A.

As used herein, a phrase referring to “at least one of” or “one or moreof” a list of items refers to any combination of those items, includingsingle members. For example, “at least one of: a, b, or c” is intendedto cover the possibilities of: a only, b only, c only, a combination ofa and b, a combination of a and c, a combination of b and c, and acombination of a and b and c.

The various illustrative components, logic, logical blocks, modules,circuits, operations, and algorithm processes described in connectionwith the implementations disclosed herein may be implemented aselectronic hardware, firmware, software, or combinations of hardware,firmware, or software, including the structures disclosed in thisspecification and the structural equivalents thereof. Theinterchangeability of hardware, firmware and software has been describedgenerally, in terms of functionality, and illustrated in the variousillustrative components, blocks, modules, circuits and processesdescribed above. Whether such functionality is implemented in hardware,firmware or software depends upon the application and design constraintsimposed on the overall system.

Various modifications to the implementations described in thisdisclosure may be readily apparent to persons having ordinary skill inthe art, and the generic principles defined herein may be applied toother implementations without departing from the spirit or scope of thisdisclosure. Thus, the claims are not intended to be limited to theimplementations shown herein but are to be accorded the widest scopeconsistent with this disclosure, the principles and the novel featuresdisclosed herein.

Additionally, various features that are described in this specificationin the context of separate implementations also can be implemented incombination in a single implementation. Conversely, various featuresthat are described in the context of a single implementation also can beimplemented in multiple implementations separately or in any suitablesubcombination. As such, although features may be described above incombination with one another, and even initially claimed as such, one ormore features from a claimed combination can in some cases be excisedfrom the combination, and the claimed combination may be directed to asubcombination or variation of a subcombination.

Similarly, while operations are depicted in the drawings in a particularorder, this should not be understood as requiring that such operationsbe performed in the particular order shown or in sequential order, orthat all illustrated operations be performed, to achieve desirableresults. Further, the drawings may schematically depict one more exampleprocesses in the form of a flowchart or flow diagram. However, otheroperations that are not depicted can be incorporated in the exampleprocesses that are schematically illustrated. For example, one or moreadditional operations can be performed before, after, simultaneously, orbetween any of the illustrated operations. In some circumstances,multitasking and parallel processing may be advantageous. Moreover, theseparation of various system components in the implementations describedabove should not be understood as requiring such separation in allimplementations, and it should be understood that the described programcomponents and systems can generally be integrated together in a singleproduct or packaged into multiple products.

What is claimed is:
 1. A lithium-sulfur battery comprising: a cathode;an anode structure positioned opposite to the cathode, the anodestructure comprising: a single layer of solid lithium configured tooutput a plurality of lithium ions; a solid-electrolyte interphase layerformed on the single layer of solid lithium; a protective layer formedon and at least partially disposed within the solid-electrolyteinterphase layer responsive to operational discharge-charge cycling ofthe lithium-sulfur battery, the protective layer comprising: a polymericbackbone chain formed of interconnected carbon atoms collectivelydefining a cooperative segmental mobility of the protective layer; aplurality of additional polymeric chains cross-linked to one another andto at least some carbon atoms of the polymeric backbone chain, eachpolymeric chain formed of interconnected monomer units; and aplasticizer dispersed throughout the protective layer without covalentlybonding to the polymeric backbone chain, the plasticizer configured toseparate adjacent monomer units of at least some of the plurality ofadditional polymeric chains, wherein an increased separation of adjacentmonomer units is associated with an increase in the cooperativesegmental mobility of the protective layer; a separator positionedbetween the anode structure and the cathode; and an electrolytedispersed throughout the cathode and in contact with the anodestructure.
 2. The lithium-sulfur battery of claim 1, wherein theprotective layer is configured to melt at a glass transitiontemperature.
 3. The lithium-sulfur battery of claim 2, wherein anincrease in the glass transition temperature is associated with areduction in the cooperative segmental mobility of the plurality ofadditional polymeric chains.
 4. The lithium-sulfur battery of claim 3,wherein a decrease in the cooperative segmental mobility of theplurality of additional polymeric chains is associated with a decreasein lithium ion (Li⁺) conductivity through the protective layer.
 5. Thelithium-sulfur battery of claim 1, wherein an increase in an amount ofthe plasticizer in the protective layer is associated with an increasein a lithium ion (Li⁺) conductivity through the protective layer.
 6. Alithium-sulfur battery comprising: a cathode; an anode positionedopposite to the cathode: a protective layer formed on the anode, theprotective layer comprising: a three-dimensional (3D) polymeric latticecomprising: a first polymeric chain and a second polymeric chainpositioned opposite one another, each of the first and second polymericchains including carbon atoms at least temporarily chemically bonded toone or more of oxide ions (O²⁻), fluorine ions (F⁻), or nitrate ions(NO³⁻); and lithium bis(trifluoromethanesulfonyl)imide (LiTFSI)dispersed throughout the 3D polymeric lattice and configured todissociate into lithium ions (Li+) and TFSI⁻ anions, the first andsecond polymeric chains configured to form the 3D polymeric lattice witha cross-linking density sufficient to trap TFSI⁻ anions by cross-linkingwith each other upon exposure to an energetic environment includingultraviolet (UV) energy and LiTFSI configured to serve as apolymerization co-initiator compound; a separator positioned between theanode and the cathode; and an electrolyte dispersed throughout thecathode and in contact with the anode.
 7. The lithium-sulfur battery ofclaim 6, wherein the first and second polymeric chains are configured toform the 3D polymeric lattice through one or more cross-linkingpolymerization reactions.
 8. The lithium-sulfur battery of claim 7,wherein one or more of the cross-linking polymerization reactionscomprises a ultraviolet (UV) curing.
 9. The lithium-sulfur battery ofclaim 8, wherein the UV curing is configured to progress at a curingrate.
 10. The lithium-sulfur battery of claim 9, wherein thepolymerization co-initiator compound is configured to increase thecuring rate.
 11. The lithium-sulfur battery of claim 6, furthercomprising a plurality of additives dispersed uniformly throughout the3D polymeric lattice, each of the plurality of additives including:lithium nitrate (LiNO₃); a plurality of inorganic ionically-conductiveceramics comprising one or more of lithium lanthanum zirconium oxide(LLZO), NASICON-type oxide Li_(1+x)Al_(x)Ti_(2-x)(PO₄)₃ (LATP) orlithium tin phosphorus sulfide (LSPS); or a plurality of nitrogen-oxygencontaining additives.
 12. The lithium-sulfur battery of claim 11,wherein the plurality of inorganic ionically-conductive ceramics areuniformly embedded in the 3D polymeric lattice.
 13. The lithium-sulfurbattery of claim 11, wherein the plurality of inorganicionically-conductive ceramics are uniformly distributed throughput theprotective layer.
 14. The lithium-sulfur battery of claim 6, wherein theprotective layer includes one or more desiccated solvents.
 15. Alithium-sulfur battery comprising: a cathode; an anode positionedopposite to the cathode: a protective layer configured to trap one ormore types of anions, the protective layer including a plurality ofingredients comprising: one or more relatively pliable oligomeric epoxybased compounds or relatively pliable oligomeric polyol based compounds;a relatively rigid polymeric epoxy based compound; one or morephoto-initiator molecules; and one or more lithium-containing saltsconfigured to dissociate into a plurality of lithium (Li+) cations andat least one type of anion; a separator positioned between the anode andthe cathode; and an electrolyte dispersed throughout the cathode and incontact with the anode.
 16. The lithium-sulfur battery of claim 15,wherein the protective layer is formed on the anode responsive toultraviolet (UV) curing of at least some of the plurality ofingredients.
 17. The lithium-sulfur battery of claim 15, wherein theprotective layer includes one or more non-reactive diluents comprising1,2-Dimethoxyethane (DME), tetrahydrofuran (THF), triethylene glycoldimethyl ether (TEGDME), or 2-Methyl-2-oxazoline (MOZ).
 18. Thelithium-sulfur battery of claim 17, wherein the protective layerincludes one or more reactive diluents comprising 1,3-Dioxolane (DOL),3,3-Dimethyloxetane (DMO), 2-Ethyl-2-oxazoline (EOZ), or ε-Caprolactone(CL).
 19. The lithium-sulfur battery of claim 18, wherein a per-unitformulation weight of the protective layer is based on a concentrationlevel of one or more non-reactive diluents or reactive diluents relativeto the plurality of ingredients of the protective layer.
 20. Thelithium-sulfur battery of claim 18, wherein the one or more reactivediluents are configured to reduce mechanical stress of at least some ofcross-linking within the protective layer.
 21. The lithium-sulfurbattery of claim 15, wherein the one or more relatively pliableoligomeric epoxy based compounds or relatively pliable oligomeric polyolbased compounds are configured to eliminate formation of pinholes in theprotective layer.
 22. The lithium-sulfur battery of claim 18, whereinthe one or more reactive diluents are configured to be removed from theprotective layer.
 23. The lithium-sulfur battery of claim 18, whereinthe one or more reactive diluents are configured to remain in theprotective layer after cross-linking of at least some of the pluralityof ingredients.
 24. The lithium-sulfur battery of claim 23, whereinretention of the one or more reactive diluents in the protective layerafter cross-linking of two or more of the plurality of ingredients isassociated with an increase in lithium ion (Li⁺) diffusion through theelectrolyte.
 25. The lithium-sulfur battery of claim 15, wherein therelatively rigid polymeric epoxy based compound is formed from aplurality of repeating epoxy monomer units.
 26. The lithium-sulfurbattery of claim 25, wherein each of the repeating epoxy monomer unitscomprises 3,4-epoxycyclohexylmethyl 3,4-epoxycyclohexanecarboxylate(ECC).
 27. The lithium-sulfur battery of claim 25, wherein each of therepeating epoxy monomer units comprises 3,4-epoxycyclohexylmethyl3,4-epoxycyclohexanecarboxylate (ECC) is configured to cross-link withadditional ECC monomer units and produce a network of polar groups. 28.The lithium-sulfur battery of claim 27, wherein the network of polargroups is configured to trap at least some anions produced upondissociation of one or more lithium-containing salts.